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How to use GST Calculator
GST Calculator. Add or remove 5%, 18% and 40% GST. From 22 September 2025 the main rates are 5% and 18%, with 40% for sin and luxury goods, plus special…
The short answer
To add GST, multiply by (1 + rate ÷ 100); to remove it, divide by that. ₹1,000 plus 18% GST is ₹1,180, and ₹1,180 including GST has ₹180 tax. ClickZM splits the tax into CGST + SGST or IGST.
It runs in your browser. What you enter is not uploaded.
How to use it
Type or paste your input into the GST Calculator.
Choose any options you need.
See the result update instantly.
Copy the result or download it.
How the result is worked out
To add GST the calculator multiplies the price by (1 + rate ÷ 100); to remove it, it divides the GST-inclusive price by the same factor. For a sale within one state the tax is split equally into CGST and SGST; for a sale between states it is shown as IGST.
The rate depends on the HSN or SAC code of the goods or service, and the GST Council sets and revises the rates. Check the current rate for your item before you issue an invoice.
Limits worth knowing
What are the GST slabs? From 22 September 2025 the main rates are 5% and 18%, with 40% for sin and luxury goods, plus special rates such as 0.25% and 3%.
CGST/SGST or IGST? Sales within a state split the tax equally into CGST and SGST; sales between states pay IGST.