GST calculator
Add GST to an amount, or pull out the GST already inside one. The split is shown both ways, because which one applies depends on where the supply goes.
The rate is yours to set. This page does not tell you which rate applies to what you sell — that depends on your goods or services, and rates get revised. Confirm yours with your CA.
CGST and SGST, or IGST — which applies to you
If your business and the place of supply are in the same state, the tax is split into CGST and SGST. If they are in different states, the whole amount is IGST instead. Your customer pays the same total either way — only the split changes.
Place of supply is not always the customer's billing address, which is where most mistakes come from. CGST, SGST and IGST explained covers that in full.
Adding GST versus extracting it
“Before GST” treats your figure as the taxable value and adds tax on top. “GST included” treats it as the final price and works backwards to find the tax already inside it.
The second one is what you need when you have quoted a customer a round all-in price and now have to put it on an invoice correctly. It is also the one people most often get wrong by simply taking a percentage off the total, which gives a different and incorrect answer.
Common questions
How do I calculate GST on an amount?
Multiply the taxable value by the GST rate that applies to what you are selling. On a bill that tax is then shown either as CGST plus SGST, or as IGST, depending on where the supply is going. The calculator above does both steps once you enter the amount and the rate.
How do I find the GST inside a price that already includes it?
Switch the calculator to “GST included”. It treats your figure as the final all-in price and works backwards to the taxable value and the tax inside it, which is what you need when you have quoted a customer a round number and now have to put it on an invoice.
When is it CGST and SGST, and when is it IGST?
If your business and the place of supply are in the same state, the tax splits into CGST and SGST, half each. If they are in different states it is a single IGST amount at the full rate. Place of supply is not always the customer’s billing address, which is where most of the mistakes come from.
Will this tell me which GST rate applies to my product?
No, and deliberately so. The rate depends on your goods or services and their HSN or SAC classification, and getting that wrong is your liability, not a calculator’s. Confirm the rate with your CA or the official rate finder, then enter it here.
Doing this on every bill instead
A calculator is useful for a one-off. For actual billing, the rate belongs on the product and the split should follow from your state and your customer's, so nobody is calculating anything at the counter.
See how to create a GST invoice for the full field list, or GST billing software for how Vanij handles it.
Vanij keeps your billing data on your own phone, not on our server.