GST Calculator
Add or remove GST at 5%, 18%, 40% or any rate and see the CGST, SGST and IGST split.
- Price before GST
- ₹1,000.00
- GST (18%)
- ₹180.00
- CGST (9%)
- ₹90.00
- SGST (9%)
- ₹90.00
- Total price incl. GST
- ₹1,180.00
GST = ₹1,000.00 × 18% = ₹180.00
How to use the GST Calculator
- Choose "Add GST" if your price is before tax, or "Remove GST" if it already includes tax.
- Enter the amount in rupees.
- Pick the GST rate — 5% and 18% are the main rates — or enter your own.
- Choose whether the sale is within your state or to another state to see the CGST/SGST or IGST split.
How GST is calculated in India
GST (Goods and Services Tax) is added to the price of most goods and services sold in India. Businesses show it on their invoices, and shoppers pay it as part of the final price. This calculator works out the tax in both directions — adding GST to a price, or finding the GST hidden inside a price you have already paid.
To add GST, multiply the price by the rate: GST on ₹1,000 at 18% is ₹180, so the total is ₹1,180. To remove GST from a price that already includes it, divide by (100 + rate) and multiply by 100: ₹1,180 × 100 ÷ 118 = ₹1,000. A common mistake is to take 18% off ₹1,180, which gives the wrong answer (₹967.60).
For a sale within one state, GST is split equally into CGST (for the central government) and SGST (for the state). At 18%, that is 9% CGST and 9% SGST. For a sale to another state, the full amount is charged as IGST.
Since GST 2.0 came into effect on 22 September 2025, most goods and services fall into two main slabs: 5% for essentials and many everyday items, and 18% as the standard rate. A special 40% rate applies to luxury and "sin" goods, and some items such as gold (3%) have their own rates. The old 12% and 28% slabs are included for checking older invoices. Always confirm the rate for a specific product or service using its HSN or SAC code.
Frequently asked questions
How do I calculate GST from a total (inclusive) amount?
Choose "Remove GST". The price before GST is total × 100 ÷ (100 + rate), and the GST is the difference. For ₹1,180 at 18%, that is ₹1,000 plus ₹180 GST.
What are the current GST rates in India?
Since 22 September 2025, the main GST slabs are 5% and 18%, with a special 40% rate on luxury and sin goods. Some items have other rates, such as 3% on gold, and some essentials are exempt. Check the HSN or SAC code of your product or service for its exact rate.
What is the difference between CGST, SGST and IGST?
For a sale within one state, GST is split equally into CGST (central) and SGST (state). For a sale from one state to another, the full GST is charged as IGST. The total tax is the same either way.
Why does subtracting 18% from the total give the wrong answer?
Because 18% GST was calculated on the price before tax, not on the total. ₹1,180 minus 18% is ₹967.60, but the real pre-tax price is ₹1,000. Always use "Remove GST" for inclusive prices.
Are the CGST and SGST amounts rounded?
Amounts are rounded to the nearest paisa. If GST cannot be split exactly in half, the extra paisa is shown in SGST so that CGST + SGST always equals the total GST.
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