GST Calculator

Add or remove GST in one click

This calculator works both directions: add GST to a base price (what should I charge?), or remove GST from a final price (how much tax is inside this bill?). It also splits the tax into CGST and SGST — each is half of the total GST for intra-state sales.

The formulas

Adding: GST amount = Base × Rate ÷ 100. Removing (reverse GST): Base = Final price × 100 ÷ (100 + Rate). The reverse calculation is the one people get wrong by hand — subtracting 18% from an 18%-inclusive price gives the wrong answer because the tax was applied to the smaller base.

Common GST rates in India

5% — essential items, economy transport. 12% — processed foods, some services. 18% — the default for most services and goods, including software and restaurants without ITC. 28% — luxury goods, automobiles. Always confirm the current rate for your specific product category, as classifications change.

For freelancers and small businesses

Quoting clients? Decide whether your quote is GST-inclusive or exclusive and say so explicitly — an 18% misunderstanding on a large invoice is a painful conversation. Use the "remove" mode to check competitor pricing and the "add" mode to build your own.