diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index e018dd23961..a1972aa16de 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -329,7 +329,7 @@ class calculate_taxes_and_totals(object):
 
 			self.doc.round_floats_in(self.doc, ["taxes_and_charges_added", "taxes_and_charges_deducted"])
 
-			self.doc.base_grand_total = flt(self.doc.grand_total * self.doc.conversion_rate) \
+			self.doc.base_grand_total = flt(self.doc.grand_total * self.doc.conversion_rate, self.doc.precision("base_grand_total")) \
 				if (self.doc.taxes_and_charges_added or self.doc.taxes_and_charges_deducted) \
 				else self.doc.base_net_total