Reverse GST Calculator
Have a price that already includes GST? Find the taxable value and the GST inside it.
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How to use the Reverse GST Calculator
- 1Enter the GST-inclusive amount.
- 2Pick the GST rate.
- 3See the taxable value and GST.
The reverse GST formula
Taxable value = inclusive amount × 100 ÷ (100 + GST rate). GST = inclusive amount − taxable value. For example, ₹5,900 at 18% → taxable ₹5,000 and GST ₹900.
When you need it
MRP-based retail, petrol bills, restaurant bills and any quote given “all inclusive” — to record purchases correctly you need the taxable value and the GST separately.
Frequently asked questions
Why not just take 18% of the amount?
Why not just take 18% of the amount?
Because the GST was charged on the smaller taxable value, not on the inclusive amount: 18% of ₹5,900 is ₹1,062, but the GST inside it is only ₹900.
Does this work for any rate?
Does this work for any rate?
Yes, choose any rate including 0.25% and 3%.
Is the result exact?
Is the result exact?
Yes — calculated to the paisa with standard half-up rounding.