A clear view of your GST calculation.

Clear answers about this calculation

These answers explain what the tool does, how the arithmetic works and where official GST guidance is still required.

What does this GST calculator calculate?

It separates the amount before GST, GST amount and total including GST.

Choose whether your starting amount excludes or includes GST, then enter the combined rate applicable to the supply.

How do I add GST to an amount?

Multiply the amount before tax by the GST rate, then add that tax to the original amount.

For example, ₹10,000 at an illustrative 18% rate gives ₹1,800 GST and ₹11,800 total.

How do I remove GST from an inclusive amount?

Divide the inclusive amount by one plus the GST rate expressed as a decimal.

For example, ₹11,800 inclusive at 18% gives ₹10,000 before tax and ₹1,800 GST. This follows the tax-inclusive calculation described in Rule 35 of the CGST Rules.

Which GST rate should I enter?

Enter the combined GST rate that applies to your specific supply.

The calculator does not classify goods or services and does not determine the legally applicable rate. Check current official rate notifications or obtain professional advice when classification is uncertain.

This is an arithmetic estimate, not an invoice or tax advice. Enter the combined GST rate applicable to your supply; the example rate is not a recommendation. Cess, reverse charge, exemptions, discounts and special valuation rules are not calculated. Figures are rounded to two decimals.