How to use the GST Calculator (Add or Remove GST)
- Enter the amount.
- Choose the GST rate for your product or service.
- Choose add GST or remove GST.
- See the GST amount and CGST/SGST split.
GST formulas
Add GST: GST = Amount × Rate ÷ 100; Total = Amount + GST.
Remove GST: Base price = Amount ÷ (1 + Rate ÷ 100); GST = Amount − Base price.
Example: ₹1,180 including 18% GST has a base price of ₹1,000 and GST of ₹180 (CGST ₹90 + SGST ₹90).
GST rates after the September 2025 reform
From 22 September 2025, GST moved to mainly two slabs: 5% for essential and merit goods and 18% as the standard rate, with 40% for luxury and sin goods. The old 12% and 28% slabs were merged into these. Special rates such as 3% on gold and 0.25% on rough diamonds continue. Check the rate for your specific HSN or SAC code on the CBIC website.
Frequently asked questions
How do I calculate GST from a total amount?
Divide the total by (1 + GST rate ÷ 100) to get the base price. The difference is the GST.
What is CGST and SGST?
For sales within a state, GST is split equally between the central government (CGST) and the state (SGST). For sales to another state, the full GST is charged as IGST.
What are the GST slabs in 2026?
The main slabs are 5% and 18%, with 40% for luxury and sin goods, plus special rates like 3% on gold.
These tools give estimates for general guidance and are not financial or tax advice. Rates and rules can change; check official sources before making decisions.