Reverse GST Calculator
Find the base price and GST from a GST-inclusive amount.
Enter your details
How it is calculated
Worked example
MRP ₹5,900 including 18% GST: base = 5,900 × 100 ÷ 118 = ₹5,000 and GST = ₹900 (not ₹1,062, which is 18% of 5,900).
About the Reverse GST Calculator
Find the base price and GST from a GST-inclusive amount. This free gst tool runs entirely in your browser: nothing you type is sent to a server, and you can save, print or download the result.
What you need to enter
You will be asked for what do you want to find?, final (gst-inclusive) amount, base price before gst (used only when finding the rate), gst rate, custom gst rate (%) — used only if "custom rate" is selected. Fields marked * are required. Every field shows a hint and the allowed range.
How to use it
- Fill in the inputs (sample values are pre-filled so you can see how it works).
- Press Calculate to see the result, breakdown and chart.
- Use Print, Download PDF or Share to keep the result, or come back to it from your saved history.
Who it helps
Salaried individuals, business owners, investors and professionals who want a quick, transparent estimate before they file, invest or plan. If your case has special facts, our team can review it - ask for a consultation.
Results are estimates based on the rules and rates described under "How it is calculated". Laws change and individual facts differ, so confirm with official sources or a qualified professional before acting. This is not tax, legal or investment advice.
Frequently asked questions
Why is GST not simply 18% of the final price?
Because the final price already contains the tax. The tax is 18% of the smaller base price, which equals 18/118 of the final amount.
Can I use this to find the rate on an invoice?
Yes — choose "GST rate" and enter the base and final amounts. If the result is not a standard slab, the invoice probably includes rounding, freight or another charge.
Need help beyond the calculator?
Talk to our tax and compliance team for advice based on your documents.