GST Calculator India Free
Add or remove GST from any amount instantly, across all standard Indian GST slabs.
How to use this tool
- 1Enter the base amount.
- 2Select the GST rate (5%, 12%, 18% or 28%).
- 3Choose whether to add GST or remove it from an inclusive amount.
- 4Read the exact tax and base breakdown instantly.
About this tool
GST calculations come up constantly for anyone running a business in India — quoting a price to a client, checking a supplier invoice, or working out what a GST-inclusive total actually breaks down to. Working backwards is where mistakes happen: subtracting 18% from a tax-inclusive figure gives the wrong answer, because the tax was charged on the smaller base, not on the total. This calculator handles both directions correctly across every standard slab and splits the result into CGST and SGST so the figures match what your invoice or filing needs. Change the rate or the amount and the breakdown updates instantly, which makes it quick to compare how a quote looks at different slabs before you send it.
Frequently Asked Questions
Which GST rates does this support?
+
All standard Indian slabs — 5%, 12%, 18% and 28%.
Can I calculate GST backward from a total that already includes tax?
+
Yes. Select 'remove GST' and enter the inclusive amount to see the base and the tax separately.
Is this accurate for GST filing?
+
It is accurate for calculation purposes. Always confirm final figures against your GST portal before filing.