How to use the GST Calculator
- Enter the amount.
- Pick the GST rate.
- Choose whether the amount already includes GST — the breakdown updates instantly.
About this tool
Adding GST: GST = amount × rate ÷ 100, and total = amount + GST.
Removing GST from an inclusive price: base = total ÷ (1 + rate ÷ 100), and GST = total − base.
For sales within the same state, GST is split equally into CGST and SGST. For inter-state sales the whole amount is IGST.
New GST rates (from 22 September 2025): most goods and services are now taxed at 5% or 18%, with a 40% rate for luxury and “sin” goods; the old 12% and 28% slabs were removed (a few items, such as tobacco, moved on a separate timeline). Rates like 3% (gold) and 0.25% still apply to specific items. Always check the current rate for your item’s HSN/SAC code — you can type any rate in the box.
Frequently asked questions
How do I calculate 18% GST on ₹1,000?
GST is ₹180, so the total is ₹1,180. Within a state that’s ₹90 CGST + ₹90 SGST.
How do I remove 18% GST from ₹1,180?
Divide by 1.18: the base price is ₹1,000 and the GST included is ₹180.
When is IGST charged instead of CGST and SGST?
IGST applies when the seller and buyer are in different states (inter-state supply).