GST Reverse Calculator India — Find Base Price from GST-Inclusive Amount

Last updated: 29 April 2026 Reviewed by Arjun Mehta, CA

The **GST reverse calculator** finds the original price of a product or service before GST was added, starting from the GST-inclusive final price. This is useful for businesses computing input tax credit, for expense reporting, or whenever you have the final bill amount and need to find the base price and GST component separately.

GST-Inclusive Amount (₹) Total amount including GST

GST Rate

Base Amount (before GST) —

GST Amount —

CGST Component —

SGST Component —

View Year-by-Year Breakdown

Real-World Examples — 2026

Software subscription at ₹23,600 (including 18% GST)

₹23,600 inclusive of 18% GST: Base = 23600 ÷ 1.18 = ₹20,000. GST = ₹3,600 (CGST ₹1,800 + SGST ₹1,800). If used for business, you can claim ITC of ₹3,600.

Hotel bill ₹14,000 inclusive of 12% GST

₹14,000 at 12% GST: Base = 14000 ÷ 1.12 = ₹12,500. GST = ₹1,500. Hotels with tariff below ₹7,500 are taxed at 12%; above ₹7,500 at 18%.

Frequently Asked Questions

How do I extract base price from a GST-inclusive amount?

Formula: Base Price = GST-Inclusive Amount ÷ (1 + GST Rate). Example: ₹11,800 at 18% GST → Base = 11800 ÷ 1.18 = ₹10,000. GST = ₹1,800.

When is reverse GST calculation needed?

Reverse calculation is needed when you receive an invoice with a GST-inclusive price and need to know the base amount for accounting, input tax credit (ITC) claims, or price comparison.

Can I claim input tax credit on all purchases?

Input tax credit (ITC) is available on GST paid for business purchases used for taxable supplies. ITC cannot be claimed on personal use, blocked credits (like cars for personal use), and exempt supplies.

Is the Reverse GST Calculator free?

Yes, the Reverse GST Calculator on CalcPhi is completely free with no registration required.

Are my inputs stored?

No. All calculations run in your browser. We do not store any financial data.

Can I use the Reverse GST Calculator on mobile?

Yes. CalcPhi is fully mobile-optimised and works on all modern smartphones.