Billing Bazaar GST calculator
Add GST to a price or take GST out of a price that already includes it. You get the base amount, the GST, the total and the CGST + SGST or IGST split.
| Price before GST | |
| GST | |
| Total price (incl. GST) |
How the GST is split
| Sale within your state | |
| CGST | |
| SGST | |
| Sale to another state | |
| IGST | |
Runs in your browser. Nothing you enter is sent to us or stored on our server.
How to use the GST calculator
- Choose Add GST if your price is before tax, or Remove GST if the price already includes GST.
- Enter the amount.
- Tap a GST rate, or type any other rate.
- Enter a quantity if you are pricing more than one unit.
- Read the base amount, GST and total, and the CGST + SGST or IGST split.
How GST is calculated
To add GST, multiply the price by the rate: ₹1,000 at 18% has ₹180 GST, so the total is ₹1,180. To remove GST from an inclusive price, divide by (100 + rate) and multiply by 100: ₹1,180 ÷ 118 × 100 = ₹1,000 base, and the rest (₹180) is GST. Taking 18% of ₹1,180 directly is a common mistake and gives the wrong answer.
CGST, SGST and IGST
When you sell within your own state, the GST is split equally into CGST (central) and SGST (state, or UTGST in a union territory) – so 18% becomes 9% + 9%. When you sell to a buyer in another state, the full GST is charged as IGST. The total tax is the same either way; only the split on the invoice changes.
Current GST rates
Since 22 September 2025 the main GST slabs are 0%, 5%, 18% and 40%, with 0.25% and 3% for a few goods such as rough diamonds and gold. Rates depend on the HSN or SAC code of each item, so check the current rate for your product on the GST portal or with the HSN code finder.
Questions people ask
How do I remove 18% GST from a price?
Divide the GST-inclusive price by 1.18. For ₹2,360, the base price is ₹2,360 ÷ 1.18 = ₹2,000 and the GST is ₹360. Choose Remove GST in the calculator to do this for any rate.
Is 18% GST split as 9% CGST and 9% SGST?
Yes, for a sale within the same state the 18% is charged as 9% CGST plus 9% SGST. For a sale to another state it is charged as 18% IGST.
What happened to the 12% and 28% GST slabs?
From 22 September 2025 most goods in the 12% slab moved to 5% and most in the 28% slab moved to 18%, while some luxury and sin goods moved to 40%. You can still type any rate in the 'Other rate' box if you need it.
Should GST be rounded on the invoice?
GST is usually worked out to the paisa for each line and the invoice total may then be rounded to the nearest rupee. This calculator shows amounts to two decimals.
Does the calculator store my numbers?
No. Everything is calculated in your browser and nothing is sent to our server.