GST Calculator
Add or remove GST from an amount at any rate.
🔒 Runs entirely in your browser — nothing is uploaded.
How GST Calculator works
How does the GST calculator work?
In "Add GST" mode it treats your amount as the pre-tax value and computes gst = amount × rate/100, then adds that to get the total. In "Remove GST" mode it treats the amount as already GST-inclusive and backs out the base price with original = amount / (1 + rate/100), so it can extract the tax component from a final price.
When would I use this?
Use "Add GST" when pricing a product or invoice from its base cost, and use "Remove GST" when you have a receipt or listed price that already includes tax and need to know the pre-tax amount and the tax portion separately.
What should I keep in mind?
The rate options are fixed at 5%, 12%, 18%, and 28%, which are India's standard GST slabs, so this tool is built around that tax structure rather than VAT or sales tax systems used elsewhere. Always confirm the applicable slab for your specific goods or services, since rates and exemptions can change.