GST Calculator

About this calculator

Indian invoices routinely need GST worked out in two opposite directions: a shopkeeper quoting a base price has to add GST on top, while someone reading a GST-inclusive total has to figure out how much of that total is actually tax. Doing this by hand means remembering whether to multiply or divide by (1 + rate/100), and it's easy to accidentally add GST to a number that already includes it, or vice versa, especially when switching between the 5%, 12%, 18% and 28% slabs used for different goods and services. This calculator takes a base amount, a GST rate, and a mode (add or remove), and returns the exact total, letting you toggle between adding GST to a quoted price and extracting the GST portion from a total you've already been billed. It's built for quick, accurate invoice checks, GST return prep, and comparing quoted prices across vendors who may present pricing GST-inclusive or GST-exclusive.

How to use this

1. 1Enter the amount, then choose whether you want to add GST to it or remove GST already included in it.
2. 2Select the applicable GST rate (5%, 12%, 18% or 28%, or enter a custom rate).
3. 3Read the GST amount and the final total instantly.

Troubleshooting

• Not sure whether to use "add" or "remove".

  Use "add" if your amount is the pre-tax price. Use "remove" if your amount already includes GST and you want to find the base price.

Frequently asked questions