Free online tool
Discount and Tax Calculator
Estimate the amount due when a percentage discount is applied before sales tax or GST. Check your invoice rules because tax treatment can vary.
How this calculator works
Discounted subtotal = original × (1 − discount ÷ 100). Tax = discounted subtotal × tax rate ÷ 100. Total = subtotal + tax.
₹1,500 less 15% is ₹1,275. At 18% tax, tax is ₹229.50 and the final total is ₹1,504.50.
Using the result well
Enter amounts using one currency consistently. The calculator displays two decimal places for money, while its internal arithmetic keeps more precision. Receipts may differ by a small amount when a seller rounds each line item separately.
For a purchase or business decision, also consider delivery fees, product quality, return conditions, taxes and any eligibility rules. A calculated saving does not by itself prove that an offer is good value.
Frequently asked questions
Is GST always calculated after a discount?
Often tax applies to the discounted transaction value, but rules and invoice practices vary. Confirm the applicable law or invoice.
Can I use this outside India?
Yes. Enter the relevant sales-tax or VAT percentage and currency amounts; the arithmetic is currency-neutral.