GST Calculator
Add GST to a price or take it out of one. Pick 5%, 18% or 40% — or any rate — and get the CGST and SGST split for a sale in your state, or IGST for one across states. Every figure adds up to the paisa.
Updated:
- Amount before GST
- ₹10,000
- CGST @ 9%
- ₹900
- SGST @ 9%
- ₹900
- Total GST
- ₹1,800
How the calculation works
| You have | Formula | Example at 18% |
|---|---|---|
| Price before GST | GST = price × rate ÷ 100 | ₹10,000 → GST ₹1,800 → total ₹11,800 |
| Price including GST | Before tax = price × 100 ÷ (100 + rate) | ₹11,800 → before tax ₹10,000 → GST ₹1,800 |
| Sale within your state | CGST = SGST = GST ÷ 2 | ₹1,800 → CGST ₹900 + SGST ₹900 |
| Sale to another state | IGST = GST | ₹1,800 → IGST ₹1,800 |
Questions people ask
How do I calculate GST on an amount?
Multiply the amount before tax by the rate. At 18%, GST on ₹10,000 is ₹10,000 × 18 ÷ 100 = ₹1,800, so the total is ₹11,800.
How do I remove GST from a price that already includes it?
Divide by (100 + rate) and multiply by 100 to get the amount before tax. For ₹1,18,000 including 18% GST: ₹1,18,000 × 100 ÷ 118 = ₹1,00,000, so the GST is ₹18,000.
What is the difference between CGST, SGST and IGST?
When the seller and the buyer are in the same state, the GST is split equally between CGST (central) and SGST (state) — or UTGST in a union territory. When the sale crosses a state border, the whole amount is charged as IGST.
What are the GST rates in India now?
Since 22 September 2025 (GST 2.0) the main slabs are 5%, 18% and 40%, with essentials at 0%. Gold, silver and jewellery stay at 3% and rough diamonds at 0.25%, and 28% continues on tobacco and pan masala. Rates are set per item, so confirm yours on the CBIC GST rate finder or with your accountant.
Why do CGST and SGST sometimes differ by one paisa?
When the total tax is an odd number of paise it can't be split evenly. This calculator gives the extra paisa to CGST so the two halves always add up to the total GST exactly.
Does this calculator save the numbers I enter?
No. The calculation runs entirely in your browser — nothing you type is sent to our servers.
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