diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index 3ad82b0..def1585 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -4,12 +4,11 @@
 from __future__ import unicode_literals
 import frappe
 from frappe import _, throw
-from frappe.utils import cint, today, flt
+from frappe.utils import today, flt
 from erpnext.setup.utils import get_company_currency, get_exchange_rate
 from erpnext.accounts.utils import get_fiscal_year, validate_fiscal_year
 from erpnext.utilities.transaction_base import TransactionBase
 from erpnext.controllers.recurring_document import convert_to_recurring, validate_recurring_document
-import json
 
 class AccountsController(TransactionBase):
 	def validate(self):
@@ -52,6 +51,14 @@
 					self.fiscal_year = get_fiscal_year(self.get(fieldname))[0]
 				break
 
+	def calculate_taxes_and_totals(self):
+		from erpnext.controllers.taxes_and_totals import taxes_and_totals
+		taxes_and_totals(self).calculate()
+
+		if self.doctype in ["Quotation", "Sales Order", "Delivery Note", "Sales Invoice"]:
+			self.calculate_commission()
+			self.calculate_contribution()
+
 	def validate_date_with_fiscal_year(self):
 		if self.meta.get_field("fiscal_year") :
 			date_field = ""
@@ -152,213 +159,11 @@
 		self.set("taxes", [])
 		self.set_taxes("taxes", "taxes_and_charges")
 
-	def calculate_taxes_and_totals(self):
-		self.discount_amount_applied = False
-		self._calculate_taxes_and_totals()
-
-		if self.meta.get_field("discount_amount"):
-			self.apply_discount_amount()
-
-	def _calculate_taxes_and_totals(self):
-		# validate conversion rate
-		company_currency = get_company_currency(self.company)
-		if not self.currency or self.currency == company_currency:
-			self.currency = company_currency
-			self.conversion_rate = 1.0
-		else:
-			validate_conversion_rate(self.currency, self.conversion_rate,
-				self.meta.get_label("conversion_rate"), self.company)
-
-		self.conversion_rate = flt(self.conversion_rate)
-
-		self.calculate_item_values()
-		self.initialize_taxes()
-
-		if hasattr(self, "determine_exclusive_rate"):
-			self.determine_exclusive_rate()
-
-		self.calculate_net_total()
-		self.calculate_taxes()
-		self.calculate_totals()
-		self._cleanup()
-
-	def initialize_taxes(self):
-		for tax in self.get("taxes"):
-			tax.item_wise_tax_detail = {}
-			tax_fields = ["total", "tax_amount_after_discount_amount",
-				"tax_amount_for_current_item", "grand_total_for_current_item",
-				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"]
-
-			if not self.discount_amount_applied:
-				tax_fields.append("tax_amount")
-
-			for fieldname in tax_fields:
-				tax.set(fieldname, 0.0)
-
-			self.validate_on_previous_row(tax)
-			self.validate_inclusive_tax(tax)
-			self.round_floats_in(tax)
-
-	def validate_on_previous_row(self, tax):
-		"""
-			validate if a valid row id is mentioned in case of
-			On Previous Row Amount and On Previous Row Total
-		"""
-		if tax.charge_type in ["On Previous Row Amount", "On Previous Row Total"] and \
-				(not tax.row_id or cint(tax.row_id) >= tax.idx):
-			throw(_("Please specify a valid Row ID for {0} in row {1}").format(_(tax.doctype), tax.idx))
-
-	def validate_inclusive_tax(self, tax):
-		def _on_previous_row_error(row_range):
-			throw(_("To include tax in row {0} in Item rate, taxes in rows {1} must also be included").format(tax.idx,
-				row_range))
-
-		if cint(getattr(tax, "included_in_print_rate", None)):
-			if tax.charge_type == "Actual":
-				# inclusive tax cannot be of type Actual
-				throw(_("Charge of type 'Actual' in row {0} cannot be included in Item Rate").format(tax.idx))
-			elif tax.charge_type == "On Previous Row Amount" and \
-					not cint(self.get("taxes")[cint(tax.row_id) - 1].included_in_print_rate):
-				# referred row should also be inclusive
-				_on_previous_row_error(tax.row_id)
-			elif tax.charge_type == "On Previous Row Total" and \
-					not all([cint(t.included_in_print_rate) for t in self.get("taxes")[:cint(tax.row_id) - 1]]):
-				# all rows about the reffered tax should be inclusive
-				_on_previous_row_error("1 - %d" % (tax.row_id,))
-
-	def calculate_taxes(self):
-		# maintain actual tax rate based on idx
-		actual_tax_dict = dict([[tax.idx, flt(tax.rate, self.precision("tax_amount", tax))] for tax in self.get("taxes")
-			if tax.charge_type == "Actual"])
-
-		for n, item in enumerate(self.get("items")):
-			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
-
-			for i, tax in enumerate(self.get("taxes")):
-				# tax_amount represents the amount of tax for the current step
-				current_tax_amount = self.get_current_tax_amount(item, tax, item_tax_map)
-
-				# Adjust divisional loss to the last item
-				if tax.charge_type == "Actual":
-					actual_tax_dict[tax.idx] -= current_tax_amount
-					if n == len(self.get("items")) - 1:
-						current_tax_amount += actual_tax_dict[tax.idx]
-
-				# store tax_amount for current item as it will be used for
-				# charge type = 'On Previous Row Amount'
-				tax.tax_amount_for_current_item = current_tax_amount
-
-				# accumulate tax amount into tax.tax_amount
-				if not self.discount_amount_applied:
-					tax.tax_amount += current_tax_amount
-
-				tax.tax_amount_after_discount_amount += current_tax_amount
-
-				if getattr(tax, "category", None):
-					# if just for valuation, do not add the tax amount in total
-					# hence, setting it as 0 for further steps
-					current_tax_amount = 0.0 if (tax.category == "Valuation") \
-						else current_tax_amount
-
-					current_tax_amount *= -1.0 if (tax.add_deduct_tax == "Deduct") else 1.0
-
-				# Calculate tax.total viz. grand total till that step
-				# note: grand_total_for_current_item contains the contribution of
-				# item's amount, previously applied tax and the current tax on that item
-				if i==0:
-					tax.grand_total_for_current_item = flt(item.base_amount + current_tax_amount,
-						self.precision("total", tax))
-				else:
-					tax.grand_total_for_current_item = \
-						flt(self.get("taxes")[i-1].grand_total_for_current_item +
-							current_tax_amount, self.precision("total", tax))
-
-				# in tax.total, accumulate grand total of each item
-				tax.total += tax.grand_total_for_current_item
-
-				# set precision in the last item iteration
-				if n == len(self.get("items")) - 1:
-					self.round_off_totals(tax)
-
-					# adjust Discount Amount loss in last tax iteration
-					if i == (len(self.get("taxes")) - 1) and self.discount_amount_applied:
-						self.adjust_discount_amount_loss(tax)
-
-	def round_off_totals(self, tax):
-		tax.total = flt(tax.total, self.precision("total", tax))
-		tax.tax_amount = flt(tax.tax_amount, self.precision("tax_amount", tax))
-		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount,
-			self.precision("tax_amount", tax))
-
-	def adjust_discount_amount_loss(self, tax):
-		discount_amount_loss = self.base_grand_total - flt(self.base_discount_amount) - tax.total
-		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount +
-			discount_amount_loss, self.precision("tax_amount", tax))
-		tax.total = flt(tax.total + discount_amount_loss, self.precision("total", tax))
-
-	def get_current_tax_amount(self, item, tax, item_tax_map):
-		tax_rate = self._get_tax_rate(tax, item_tax_map)
-		current_tax_amount = 0.0
-
-		if tax.charge_type == "Actual":
-			# distribute the tax amount proportionally to each item row
-			actual = flt(tax.rate, self.precision("tax_amount", tax))
-			current_tax_amount = (self.base_net_total
-				and ((item.base_amount / self.base_net_total) * actual)
-				or 0)
-		elif tax.charge_type == "On Net Total":
-			current_tax_amount = (tax_rate / 100.0) * item.base_amount
-		elif tax.charge_type == "On Previous Row Amount":
-			current_tax_amount = (tax_rate / 100.0) * \
-				self.get("taxes")[cint(tax.row_id) - 1].tax_amount_for_current_item
-		elif tax.charge_type == "On Previous Row Total":
-			current_tax_amount = (tax_rate / 100.0) * \
-				self.get("taxes")[cint(tax.row_id) - 1].grand_total_for_current_item
-
-		current_tax_amount = flt(current_tax_amount, self.precision("tax_amount", tax))
-
-		# store tax breakup for each item
-		key = item.item_code or item.item_name
-		if tax.item_wise_tax_detail.get(key):
-			item_wise_tax_amount = tax.item_wise_tax_detail[key][1] + current_tax_amount
-			tax.item_wise_tax_detail[key] = [tax_rate,item_wise_tax_amount]
-		else:
-			tax.item_wise_tax_detail[key] = [tax_rate,current_tax_amount]
-
-		return current_tax_amount
-
-	def _load_item_tax_rate(self, item_tax_rate):
-		return json.loads(item_tax_rate) if item_tax_rate else {}
-
-	def _get_tax_rate(self, tax, item_tax_map):
-		if item_tax_map.has_key(tax.account_head):
-			return flt(item_tax_map.get(tax.account_head), self.precision("rate", tax))
-		else:
-			return tax.rate
-
-	def _cleanup(self):
-		for tax in self.get("taxes"):
-			tax.item_wise_tax_detail = json.dumps(tax.item_wise_tax_detail, separators=(',', ':'))
-
-	def _set_in_company_currency(self, item, print_field, base_field):
-		"""set values in base currency"""
-		value_in_company_currency = flt(self.conversion_rate *
-			flt(item.get(print_field), self.precision(print_field, item)), self.precision(base_field, item))
-		item.set(base_field, value_in_company_currency)
-
 	def validate_enabled_taxes_and_charges(self):
 		taxes_and_charges_doctype = self.meta.get_options("taxes_and_charges")
 		if frappe.db.get_value(taxes_and_charges_doctype, self.taxes_and_charges, "disabled"):
 			frappe.throw(_("{0} '{1}' is disabled").format(taxes_and_charges_doctype, self.taxes_and_charges))
 
-	def calculate_total_advance(self, parenttype, advance_parentfield):
-		if self.doctype == parenttype and self.docstatus < 2:
-			sum_of_allocated_amount = sum([flt(adv.allocated_amount, self.precision("allocated_amount", adv))
-				for adv in self.get(advance_parentfield)])
-
-			self.total_advance = flt(sum_of_allocated_amount, self.precision("total_advance"))
-
-			self.calculate_outstanding_amount()
 
 	def get_gl_dict(self, args):
 		"""this method populates the common properties of a gl entry record"""
diff --git a/erpnext/controllers/buying_controller.py b/erpnext/controllers/buying_controller.py
index fb7fb31..93a0145 100644
--- a/erpnext/controllers/buying_controller.py
+++ b/erpnext/controllers/buying_controller.py
@@ -4,7 +4,7 @@
 from __future__ import unicode_literals
 import frappe
 from frappe import _, msgprint
-from frappe.utils import flt, rounded
+from frappe.utils import flt
 
 from erpnext.setup.utils import get_company_currency
 from erpnext.accounts.party import get_party_details
@@ -79,82 +79,6 @@
 		if self.meta.get_field("in_words"):
 			self.in_words = money_in_words(self.grand_total, self.currency)
 
-	def calculate_taxes_and_totals(self):
-		super(BuyingController, self).calculate_taxes_and_totals()
-		self.calculate_total_advance("Purchase Invoice", "advances")
-
-	def calculate_item_values(self):
-		for item in self.get("items"):
-			self.round_floats_in(item)
-
-			if item.discount_percentage == 100.0:
-				item.rate = 0.0
-			elif not item.rate:
-				item.rate = flt(item.price_list_rate * (1.0 - (item.discount_percentage / 100.0)),
-					self.precision("rate", item))
-
-			item.amount = flt(item.rate * item.qty, self.precision("amount", item))
-			item.item_tax_amount = 0.0;
-
-			self._set_in_company_currency(item, "amount", "base_amount")
-			self._set_in_company_currency(item, "price_list_rate", "base_price_list_rate")
-			self._set_in_company_currency(item, "rate", "base_rate")
-
-
-	def calculate_net_total(self):
-		self.base_net_total = self.net_total = 0.0
-
-		for item in self.get("items"):
-			self.base_net_total += item.base_amount
-			self.net_total += item.amount
-
-		self.round_floats_in(self, ["base_net_total", "net_total"])
-
-	def calculate_totals(self):
-		self.base_grand_total = flt(self.get("taxes")[-1].total if self.get("taxes") else self.base_net_total)
-
-		self.base_total_taxes_and_charges = flt(self.base_grand_total - self.base_net_total, self.precision("base_total_taxes_and_charges"))
-
-		self.base_grand_total = flt(self.base_grand_total, self.precision("base_grand_total"))
-
-		if self.meta.get_field("base_rounded_total"):
-			self.base_rounded_total = rounded(self.base_grand_total)
-
-		if self.meta.get_field("base_taxes_and_charges_added"):
-			self.base_taxes_and_charges_added = flt(sum([flt(d.tax_amount) for d in self.get("taxes")
-				if d.add_deduct_tax=="Add" and d.category in ["Valuation and Total", "Total"]]),
-				self.precision("base_taxes_and_charges_added"))
-
-		if self.meta.get_field("base_taxes_and_charges_deducted"):
-			self.base_taxes_and_charges_deducted = flt(sum([flt(d.tax_amount) for d in self.get("taxes")
-				if d.add_deduct_tax=="Deduct" and d.category in ["Valuation and Total", "Total"]]),
-				self.precision("base_taxes_and_charges_deducted"))
-
-		self.grand_total = flt(self.base_grand_total / self.conversion_rate) \
-			if (self.base_taxes_and_charges_added or self.base_taxes_and_charges_deducted) else self.net_total
-
-		self.grand_total = flt(self.grand_total, self.precision("grand_total"))
-
-		if self.meta.get_field("rounded_total"):
-			self.rounded_total = rounded(self.grand_total)
-
-		if self.meta.get_field("taxes_and_charges_added"):
-			self.taxes_and_charges_added = flt(self.base_taxes_and_charges_added /
-				self.conversion_rate, self.precision("taxes_and_charges_added"))
-
-		if self.meta.get_field("taxes_and_charges_deducted"):
-			self.taxes_and_charges_deducted = flt(self.base_taxes_and_charges_deducted /
-				self.conversion_rate, self.precision("taxes_and_charges_deducted"))
-
-	def calculate_outstanding_amount(self):
-		if self.doctype == "Purchase Invoice" and self.docstatus == 0:
-			self.total_advance = flt(self.total_advance,
-				self.precision("total_advance"))
-			self.total_amount_to_pay = flt(self.base_grand_total - flt(self.write_off_amount,
-				self.precision("write_off_amount")), self.precision("total_amount_to_pay"))
-			self.outstanding_amount = flt(self.total_amount_to_pay - self.total_advance,
-				self.precision("outstanding_amount"))
-
 	# update valuation rate
 	def update_valuation_rate(self, parentfield):
 		"""
diff --git a/erpnext/controllers/selling_controller.py b/erpnext/controllers/selling_controller.py
index 41586c8..40c2232 100644
--- a/erpnext/controllers/selling_controller.py
+++ b/erpnext/controllers/selling_controller.py
@@ -3,7 +3,7 @@
 
 from __future__ import unicode_literals
 import frappe
-from frappe.utils import cint, flt, rounded, cstr, comma_or
+from frappe.utils import cint, flt, cstr, comma_or
 from erpnext.setup.utils import get_company_currency
 from frappe import _, throw
 from erpnext.stock.get_item_details import get_available_qty
@@ -121,157 +121,6 @@
 			self.in_words = money_in_words(disable_rounded_total and
 				self.grand_total or self.rounded_total, self.currency)
 
-	def calculate_taxes_and_totals(self):
-		super(SellingController, self).calculate_taxes_and_totals()
-
-		self.calculate_total_advance("Sales Invoice", "advances")
-		self.calculate_commission()
-		self.calculate_contribution()
-
-	def determine_exclusive_rate(self):
-		if not any((cint(tax.included_in_print_rate) for tax in self.get("taxes"))):
-			# no inclusive tax
-			return
-
-		for item in self.get("items"):
-			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
-			cumulated_tax_fraction = 0
-			for i, tax in enumerate(self.get("taxes")):
-				tax.tax_fraction_for_current_item = self.get_current_tax_fraction(tax, item_tax_map)
-
-				if i==0:
-					tax.grand_total_fraction_for_current_item = 1 + tax.tax_fraction_for_current_item
-				else:
-					tax.grand_total_fraction_for_current_item = \
-						self.get("taxes")[i-1].grand_total_fraction_for_current_item \
-						+ tax.tax_fraction_for_current_item
-
-				cumulated_tax_fraction += tax.tax_fraction_for_current_item
-
-			if cumulated_tax_fraction and not self.discount_amount_applied and item.qty:
-				item.base_amount = flt((item.amount * self.conversion_rate) /
-					(1 + cumulated_tax_fraction), self.precision("base_amount", item))
-
-				item.base_rate = flt(item.base_amount / item.qty, self.precision("base_rate", item))
-				item.discount_percentage = flt(item.discount_percentage, self.precision("discount_percentage", item))
-
-				if item.discount_percentage == 100:
-					item.base_price_list_rate = item.base_rate
-					item.base_rate = 0.0
-				else:
-					item.base_price_list_rate = flt(item.base_rate / (1 - (item.discount_percentage / 100.0)),
-						self.precision("base_price_list_rate", item))
-
-	def get_current_tax_fraction(self, tax, item_tax_map):
-		"""
-			Get tax fraction for calculating tax exclusive amount
-			from tax inclusive amount
-		"""
-		current_tax_fraction = 0
-
-		if cint(tax.included_in_print_rate):
-			tax_rate = self._get_tax_rate(tax, item_tax_map)
-
-			if tax.charge_type == "On Net Total":
-				current_tax_fraction = tax_rate / 100.0
-
-			elif tax.charge_type == "On Previous Row Amount":
-				current_tax_fraction = (tax_rate / 100.0) * \
-					self.get("taxes")[cint(tax.row_id) - 1].tax_fraction_for_current_item
-
-			elif tax.charge_type == "On Previous Row Total":
-				current_tax_fraction = (tax_rate / 100.0) * \
-					self.get("taxes")[cint(tax.row_id) - 1].grand_total_fraction_for_current_item
-
-		return current_tax_fraction
-
-	def calculate_item_values(self):
-		if not self.discount_amount_applied:
-			for item in self.get("items"):
-				self.round_floats_in(item)
-
-				if item.discount_percentage == 100:
-					item.rate = 0
-				elif not item.rate:
-					item.rate = flt(item.price_list_rate * (1.0 - (item.discount_percentage / 100.0)),
-						self.precision("rate", item))
-
-				item.amount = flt(item.rate * item.qty,
-					self.precision("amount", item))
-
-				self._set_in_company_currency(item, "price_list_rate", "base_price_list_rate")
-				self._set_in_company_currency(item, "rate", "base_rate")
-				self._set_in_company_currency(item, "amount", "base_amount")
-
-	def calculate_net_total(self):
-		self.base_net_total = self.net_total = 0.0
-
-		for item in self.get("items"):
-			self.base_net_total += item.base_amount
-			self.net_total += item.amount
-
-		self.round_floats_in(self, ["base_net_total", "net_total"])
-
-	def calculate_totals(self):
-		self.base_grand_total = flt(self.get("taxes")[-1].total if self.get("taxes") else self.base_net_total)
-
-		self.base_total_taxes_and_charges = flt(self.base_grand_total - self.base_net_total, self.precision("base_total_taxes_and_charges"))
-
-		self.grand_total = flt(self.base_grand_total / self.conversion_rate) \
-			if (self.base_total_taxes_and_charges or self.discount_amount) else self.net_total
-
-		self.total_taxes_and_charges = flt(self.grand_total - self.net_total +
-			flt(self.discount_amount), self.precision("total_taxes_and_charges"))
-
-		self.base_grand_total = flt(self.base_grand_total, self.precision("base_grand_total"))
-		self.grand_total = flt(self.grand_total, self.precision("grand_total"))
-
-		self.base_rounded_total = rounded(self.base_grand_total)
-		self.rounded_total = rounded(self.grand_total)
-
-	def apply_discount_amount(self):
-		if self.discount_amount:
-			self.base_discount_amount = flt(self.discount_amount * self.conversion_rate, self.precision("base_discount_amount"))
-
-			grand_total_for_discount_amount = self.get_grand_total_for_discount_amount()
-
-			if grand_total_for_discount_amount:
-				# calculate item amount after Discount Amount
-				for item in self.get("items"):
-					distributed_amount = flt(self.base_discount_amount) * item.base_amount / grand_total_for_discount_amount
-					item.base_amount = flt(item.base_amount - distributed_amount, self.precision("base_amount", item))
-
-				self.discount_amount_applied = True
-				self._calculate_taxes_and_totals()
-		else:
-			self.base_discount_amount = 0
-
-	def get_grand_total_for_discount_amount(self):
-		actual_taxes_dict = {}
-
-		for tax in self.get("taxes"):
-			if tax.charge_type == "Actual":
-				actual_taxes_dict.setdefault(tax.idx, tax.tax_amount)
-			elif tax.row_id in actual_taxes_dict:
-				actual_tax_amount = flt(actual_taxes_dict.get(tax.row_id, 0)) * \
-					flt(tax.rate) / 100
-				actual_taxes_dict.setdefault(tax.idx, actual_tax_amount)
-
-		grand_total_for_discount_amount = flt(self.base_grand_total - sum(actual_taxes_dict.values()),
-			self.precision("base_grand_total"))
-		return grand_total_for_discount_amount
-
-	def calculate_outstanding_amount(self):
-		# NOTE:
-		# write_off_amount is only for POS Invoice
-		# total_advance is only for non POS Invoice
-		if self.doctype == "Sales Invoice" and self.docstatus == 0:
-			self.round_floats_in(self, ["base_grand_total", "total_advance", "write_off_amount",
-				"paid_amount"])
-			total_amount_to_pay = self.base_grand_total - self.write_off_amount
-			self.outstanding_amount = flt(total_amount_to_pay - self.total_advance \
-				- self.paid_amount,	self.precision("outstanding_amount"))
-
 	def calculate_commission(self):
 		if self.meta.get_field("commission_rate"):
 			self.round_floats_in(self, ["base_net_total", "commission_rate"])
diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
new file mode 100644
index 0000000..321417f
--- /dev/null
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -0,0 +1,397 @@
+# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
+# License: GNU General Public License v3. See license.txt
+
+from __future__ import unicode_literals
+import json
+from frappe import _, throw
+from frappe.utils import cint, flt, rounded
+from erpnext.setup.utils import get_company_currency
+from erpnext.controllers.accounts_controller import validate_conversion_rate
+
+class taxes_and_totals(object):
+	def __init__(self, doc):
+		self.doc = doc
+
+	def calculate(self):
+		self.discount_amount_applied = False
+		self._calculate()
+
+		if self.doc.meta.get_field("discount_amount"):
+			self.apply_discount_amount()
+
+		if self.doctype in ["Sales Invoice", "Purchase Invoice"]:
+			self.calculate_total_advance()
+
+	def _calculate(self):
+		# validate conversion rate
+		company_currency = get_company_currency(self.doc.company)
+		if not self.doc.currency or self.doc.currency == company_currency:
+			self.doc.currency = company_currency
+			self.doc.conversion_rate = 1.0
+		else:
+			validate_conversion_rate(self.doc.currency, self.doc.conversion_rate,
+				self.doc.meta.get_label("conversion_rate"), self.doc.company)
+
+		self.doc.conversion_rate = flt(self.doc.conversion_rate)
+
+		self.calculate_item_values()
+		self.initialize_taxes()
+
+		if self.doctype in ["Quotation", "Sales Order", "Delivery Note", "Sales Invoice"]:
+			self.determine_exclusive_rate()
+
+		self.calculate_net_total()
+		self.calculate_taxes()
+		self.calculate_totals()
+		self._cleanup()
+
+	def calculate_item_values(self):
+		if not self.discount_amount_applied:
+			for item in self.doc.get("items"):
+				self.doc.round_floats_in(item)
+
+				if item.discount_percentage == 100:
+					item.rate = 0.0
+				elif not item.rate:
+					item.rate = flt(item.price_list_rate * (1.0 - (item.discount_percentage / 100.0)),
+						self.doc.precision("rate", item))
+
+				item.amount = flt(item.rate * item.qty,	self.doc.precision("amount", item))
+				item.item_tax_amount = 0.0;
+
+				self._set_in_company_currency(item, "price_list_rate", "base_price_list_rate")
+				self._set_in_company_currency(item, "rate", "base_rate")
+				self._set_in_company_currency(item, "amount", "base_amount")
+
+	def _set_in_company_currency(self, item, print_field, base_field):
+		"""set values in base currency"""
+		value_in_company_currency = flt(self.doc.conversion_rate *
+			flt(item.get(print_field), self.doc.precision(print_field, item)), self.doc.precision(base_field, item))
+		item.set(base_field, value_in_company_currency)
+
+	def initialize_taxes(self):
+		for tax in self.doc.get("taxes"):
+			tax.item_wise_tax_detail = {}
+			tax_fields = ["total", "tax_amount_after_discount_amount",
+				"tax_amount_for_current_item", "grand_total_for_current_item",
+				"tax_fraction_for_current_item", "grand_total_fraction_for_current_item"]
+
+			if not self.discount_amount_applied:
+				tax_fields.append("tax_amount")
+
+			for fieldname in tax_fields:
+				tax.set(fieldname, 0.0)
+
+			self.validate_on_previous_row(tax)
+			self.validate_inclusive_tax(tax)
+			self.doc.round_floats_in(tax)
+
+	def validate_on_previous_row(self, tax):
+		"""
+			validate if a valid row id is mentioned in case of
+			On Previous Row Amount and On Previous Row Total
+		"""
+		if tax.charge_type in ["On Previous Row Amount", "On Previous Row Total"] and \
+				(not tax.row_id or cint(tax.row_id) >= tax.idx):
+			throw(_("Please specify a valid Row ID for {0} in row {1}").format(_(tax.doctype), tax.idx))
+
+	def validate_inclusive_tax(self, tax):
+		def _on_previous_row_error(row_range):
+			throw(_("To include tax in row {0} in Item rate, taxes in rows {1} must also be included").format(tax.idx,
+				row_range))
+
+		if cint(getattr(tax, "included_in_print_rate", None)):
+			if tax.charge_type == "Actual":
+				# inclusive tax cannot be of type Actual
+				throw(_("Charge of type 'Actual' in row {0} cannot be included in Item Rate").format(tax.idx))
+			elif tax.charge_type == "On Previous Row Amount" and \
+					not cint(self.doc.get("taxes")[cint(tax.row_id) - 1].included_in_print_rate):
+				# referred row should also be inclusive
+				_on_previous_row_error(tax.row_id)
+			elif tax.charge_type == "On Previous Row Total" and \
+					not all([cint(t.included_in_print_rate) for t in self.doc.get("taxes")[:cint(tax.row_id) - 1]]):
+				# all rows about the reffered tax should be inclusive
+				_on_previous_row_error("1 - %d" % (tax.row_id,))
+
+	def determine_exclusive_rate(self):
+		if not any((cint(tax.included_in_print_rate) for tax in self.doc.get("taxes"))):
+			# no inclusive tax
+			return
+
+		for item in self.doc.get("items"):
+			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
+			cumulated_tax_fraction = 0
+			for i, tax in enumerate(self.doc.get("taxes")):
+				tax.tax_fraction_for_current_item = self.get_current_tax_fraction(tax, item_tax_map)
+
+				if i==0:
+					tax.grand_total_fraction_for_current_item = 1 + tax.tax_fraction_for_current_item
+				else:
+					tax.grand_total_fraction_for_current_item = \
+						self.doc.get("taxes")[i-1].grand_total_fraction_for_current_item \
+						+ tax.tax_fraction_for_current_item
+
+				cumulated_tax_fraction += tax.tax_fraction_for_current_item
+
+			if cumulated_tax_fraction and not self.discount_amount_applied and item.qty:
+				item.base_amount = flt((item.amount * self.doc.conversion_rate) /
+					(1 + cumulated_tax_fraction), self.doc.precision("base_amount", item))
+
+				item.base_rate = flt(item.base_amount / item.qty, self.doc.precision("base_rate", item))
+				item.discount_percentage = flt(item.discount_percentage, self.doc.precision("discount_percentage", item))
+
+				if item.discount_percentage == 100:
+					item.base_price_list_rate = item.base_rate
+					item.base_rate = 0.0
+				else:
+					item.base_price_list_rate = flt(item.base_rate / (1 - (item.discount_percentage / 100.0)),
+						self.doc.precision("base_price_list_rate", item))
+
+	def _load_item_tax_rate(self, item_tax_rate):
+		return json.loads(item_tax_rate) if item_tax_rate else {}
+
+	def get_current_tax_fraction(self, tax, item_tax_map):
+		"""
+			Get tax fraction for calculating tax exclusive amount
+			from tax inclusive amount
+		"""
+		current_tax_fraction = 0
+
+		if cint(tax.included_in_print_rate):
+			tax_rate = self._get_tax_rate(tax, item_tax_map)
+
+			if tax.charge_type == "On Net Total":
+				current_tax_fraction = tax_rate / 100.0
+
+			elif tax.charge_type == "On Previous Row Amount":
+				current_tax_fraction = (tax_rate / 100.0) * \
+					self.doc.get("taxes")[cint(tax.row_id) - 1].tax_fraction_for_current_item
+
+			elif tax.charge_type == "On Previous Row Total":
+				current_tax_fraction = (tax_rate / 100.0) * \
+					self.doc.get("taxes")[cint(tax.row_id) - 1].grand_total_fraction_for_current_item
+
+		return current_tax_fraction
+
+	def _get_tax_rate(self, tax, item_tax_map):
+		if item_tax_map.has_key(tax.account_head):
+			return flt(item_tax_map.get(tax.account_head), self.doc.precision("rate", tax))
+		else:
+			return tax.rate
+
+	def calculate_net_total(self):
+		self.doc.base_net_total = self.doc.net_total = 0.0
+
+		for item in self.doc.get("items"):
+			self.doc.base_net_total += item.base_amount
+			self.doc.net_total += item.amount
+
+		self.round_floats_in(self.doc, ["base_net_total", "net_total"])
+
+	def calculate_taxes(self):
+		# maintain actual tax rate based on idx
+		actual_tax_dict = dict([[tax.idx, flt(tax.rate, self.doc.precision("tax_amount", tax))]
+			for tax in self.doc.get("taxes") if tax.charge_type == "Actual"])
+
+		for n, item in enumerate(self.doc.get("items")):
+			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
+
+			for i, tax in enumerate(self.doc.get("taxes")):
+				# tax_amount represents the amount of tax for the current step
+				current_tax_amount = self.get_current_tax_amount(item, tax, item_tax_map)
+
+				# Adjust divisional loss to the last item
+				if tax.charge_type == "Actual":
+					actual_tax_dict[tax.idx] -= current_tax_amount
+					if n == len(self.doc.get("items")) - 1:
+						current_tax_amount += actual_tax_dict[tax.idx]
+
+				# store tax_amount for current item as it will be used for
+				# charge type = 'On Previous Row Amount'
+				tax.tax_amount_for_current_item = current_tax_amount
+
+				# accumulate tax amount into tax.tax_amount
+				if not self.discount_amount_applied:
+					tax.tax_amount += current_tax_amount
+
+				tax.tax_amount_after_discount_amount += current_tax_amount
+
+				if getattr(tax, "category", None):
+					# if just for valuation, do not add the tax amount in total
+					# hence, setting it as 0 for further steps
+					current_tax_amount = 0.0 if (tax.category == "Valuation") \
+						else current_tax_amount
+
+					current_tax_amount *= -1.0 if (tax.add_deduct_tax == "Deduct") else 1.0
+
+				# Calculate tax.total viz. grand total till that step
+				# note: grand_total_for_current_item contains the contribution of
+				# item's amount, previously applied tax and the current tax on that item
+				if i==0:
+					tax.grand_total_for_current_item = flt(item.base_amount + current_tax_amount,
+						self.doc.precision("total", tax))
+				else:
+					tax.grand_total_for_current_item = \
+						flt(self.doc.get("taxes")[i-1].grand_total_for_current_item +
+							current_tax_amount, self.doc.precision("total", tax))
+
+				# in tax.total, accumulate grand total of each item
+				tax.total += tax.grand_total_for_current_item
+
+				# set precision in the last item iteration
+				if n == len(self.doc.get("items")) - 1:
+					self.round_off_totals(tax)
+
+					# adjust Discount Amount loss in last tax iteration
+					if i == (len(self.doc.get("taxes")) - 1) and self.discount_amount_applied:
+						self.adjust_discount_amount_loss(tax)
+
+	def get_current_tax_amount(self, item, tax, item_tax_map):
+		tax_rate = self._get_tax_rate(tax, item_tax_map)
+		current_tax_amount = 0.0
+
+		if tax.charge_type == "Actual":
+			# distribute the tax amount proportionally to each item row
+			actual = flt(tax.rate, self.doc.precision("tax_amount", tax))
+			current_tax_amount = (self.doc.base_net_total
+				and ((item.base_amount / self.doc.base_net_total) * actual)
+				or 0)
+		elif tax.charge_type == "On Net Total":
+			current_tax_amount = (tax_rate / 100.0) * item.base_amount
+		elif tax.charge_type == "On Previous Row Amount":
+			current_tax_amount = (tax_rate / 100.0) * \
+				self.doc.get("taxes")[cint(tax.row_id) - 1].tax_amount_for_current_item
+		elif tax.charge_type == "On Previous Row Total":
+			current_tax_amount = (tax_rate / 100.0) * \
+				self.doc.get("taxes")[cint(tax.row_id) - 1].grand_total_for_current_item
+
+		current_tax_amount = flt(current_tax_amount, self.doc.precision("tax_amount", tax))
+
+		# store tax breakup for each item
+		key = item.item_code or item.item_name
+		if tax.item_wise_tax_detail.get(key):
+			item_wise_tax_amount = tax.item_wise_tax_detail[key][1] + current_tax_amount
+			tax.item_wise_tax_detail[key] = [tax_rate,item_wise_tax_amount]
+		else:
+			tax.item_wise_tax_detail[key] = [tax_rate,current_tax_amount]
+
+		return current_tax_amount
+
+	def round_off_totals(self, tax):
+		tax.total = flt(tax.total, self.doc.precision("total", tax))
+		tax.tax_amount = flt(tax.tax_amount, self.doc.precision("tax_amount", tax))
+		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount,
+			self.doc.precision("tax_amount", tax))
+
+	def adjust_discount_amount_loss(self, tax):
+		discount_amount_loss = self.doc.base_grand_total - flt(self.doc.base_discount_amount) - tax.total
+		tax.tax_amount_after_discount_amount = flt(tax.tax_amount_after_discount_amount +
+			discount_amount_loss, self.doc.precision("tax_amount", tax))
+		tax.total = flt(tax.total + discount_amount_loss, self.doc.precision("total", tax))
+
+	def calculate_totals(self):
+		self.doc.base_grand_total = flt(self.doc.get("taxes")[-1].total
+			if self.doc.get("taxes") else self.doc.base_net_total)
+
+		self.doc.base_total_taxes_and_charges = flt(self.doc.base_grand_total - self.doc.base_net_total,
+			self.doc.precision("base_total_taxes_and_charges"))
+
+		if self.doctype in ["Quotation", "Sales Order", "Delivery Note", "Sales Invoice"]:
+			self.doc.grand_total = flt(self.doc.base_grand_total / self.doc.conversion_rate) \
+				if (self.doc.base_total_taxes_and_charges or self.doc.discount_amount) else self.doc.net_total
+
+			self.doc.total_taxes_and_charges = flt(self.doc.grand_total - self.doc.net_total +
+				flt(self.doc.discount_amount), self.doc.precision("total_taxes_and_charges"))
+		else:
+			self.doc.base_taxes_and_charges_added, self.base_taxes_and_charges_deducted = 0.0, 0.0
+			for tax in self.doc.get("taxes"):
+				if tax.category in ["Valuation and Total", "Total"]:
+					if tax.add_deduct_tax == "Add":
+						self.doc.base_taxes_and_charges_added += flt(tax.tax_amount)
+					else:
+						self.doc.base_taxes_and_charges_deducted += flt(tax.tax_amount)
+
+			self.doc.round_floats_in(self.doc, ["base_taxes_and_charges_added", "base_taxes_and_charges_deducted"])
+
+			self.doc.grand_total = flt(self.doc.base_grand_total / self.doc.conversion_rate) \
+				if (self.doc.base_taxes_and_charges_added or self.doc.base_taxes_and_charges_deducted) else self.doc.net_total
+
+			self.doc.total_taxes_and_charges = flt(self.doc.grand_total - self.doc.net_total,
+				self.doc.precision("total_taxes_and_charges"))
+
+			self.doc.taxes_and_charges_added = flt(self.doc.base_taxes_and_charges_added / self.doc.conversion_rate,
+				self.doc.precision("taxes_and_charges_added"))
+			self.doc.taxes_and_charges_deducted = flt(self.doc.base_taxes_and_charges_deducted / self.doc.conversion_rate,
+				self.doc.precision("taxes_and_charges_deducted"))
+
+		self.doc.base_grand_total = flt(self.doc.base_grand_total, self.doc.precision("base_grand_total"))
+		self.doc.grand_total = flt(self.doc.grand_total, self.doc.precision("grand_total"))
+
+		if self.doc.meta.get_field("base_rounded_total"):
+			self.doc.base_rounded_total = rounded(self.doc.base_grand_total)
+		if self.doc.meta.get_field("rounded_total"):
+			self.doc.rounded_total = rounded(self.doc.grand_total)
+
+	def _cleanup(self):
+		for tax in self.doc.get("taxes"):
+			tax.item_wise_tax_detail = json.dumps(tax.item_wise_tax_detail, separators=(',', ':'))
+
+	def apply_discount_amount(self):
+		if self.doc.discount_amount:
+			self.doc.base_discount_amount = flt(self.doc.discount_amount * self.doc.conversion_rate,
+				self.doc.precision("base_discount_amount"))
+
+			grand_total_for_discount_amount = self.get_grand_total_for_discount_amount()
+
+			if grand_total_for_discount_amount:
+				# calculate item amount after Discount Amount
+				for item in self.doc.get("items"):
+					distributed_amount = flt(self.doc.base_discount_amount) * item.base_amount / grand_total_for_discount_amount
+					item.base_amount = flt(item.base_amount - distributed_amount, self.doc.precision("base_amount", item))
+
+				self.discount_amount_applied = True
+				self._calculate()
+		else:
+			self.doc.base_discount_amount = 0
+
+	def get_grand_total_for_discount_amount(self):
+		actual_taxes_dict = {}
+
+		for tax in self.doc.get("taxes"):
+			if tax.charge_type == "Actual":
+				actual_taxes_dict.setdefault(tax.idx, tax.tax_amount)
+			elif tax.row_id in actual_taxes_dict:
+				actual_tax_amount = flt(actual_taxes_dict.get(tax.row_id, 0)) * flt(tax.rate) / 100
+				actual_taxes_dict.setdefault(tax.idx, actual_tax_amount)
+
+		grand_total_for_discount_amount = flt(self.doc.base_grand_total - sum(actual_taxes_dict.values()),
+			self.doc.precision("base_grand_total"))
+		return grand_total_for_discount_amount
+
+
+	def calculate_total_advance(self, parenttype, advance_parentfield):
+		if self.docstatus < 2:
+			sum_of_allocated_amount = sum([flt(adv.allocated_amount, self.doc.precision("allocated_amount", adv))
+				for adv in self.doc.get("advances")])
+
+			self.doc.total_advance = flt(sum_of_allocated_amount, self.doc.precision("total_advance"))
+
+			if self.docstatus == 0:
+				self.calculate_outstanding_amount()
+
+	def calculate_outstanding_amount(self):
+		# NOTE:
+		# write_off_amount is only for POS Invoice
+		# total_advance is only for non POS Invoice
+
+		if self.doctype == "Sales Invoice":
+			self.round_floats_in(self.doc, ["base_grand_total", "total_advance", "write_off_amount", "paid_amount"])
+			total_amount_to_pay = self.doc.base_grand_total - self.doc.write_off_amount
+			self.doc.outstanding_amount = flt(total_amount_to_pay - self.doc.total_advance - self.doc.paid_amount,
+				self.doc.precision("outstanding_amount"))
+		else:
+			self.round_floats_in(self.doc, ["total_advance", "write_off_amount"])
+			self.doc.total_amount_to_pay = flt(self.doc.base_grand_total - self.doc.write_off_amount,
+				self.doc.precision("total_amount_to_pay"))
+			self.doc.outstanding_amount = flt(self.doc.total_amount_to_pay - self.doc.total_advance,
+				self.doc.precision("outstanding_amount"))