GST Calculator
Add or remove GST at any rate — 5%, 18%, 40%, or a custom slab.
GST slabs and rates are tentative, not official — the government revises them from time to time. Always verify the current rate for your specific goods/services before relying on this for real invoicing or filing.
Calculate GST both ways: add GST to a pre-tax amount to get the total, or pull the GST amount back out of a tax-inclusive price. Covers India's current GST slabs (5% and 18% standard, 40% for luxury/sin goods) plus any custom rate.
How to calculate GST
- Adding GST: GST = price × rate. Total = price × (1 + rate).
- Removing GST from an inclusive price: price before GST = total ÷ (1 + rate). GST = total − price before GST.
Worked examples
| Situation | Calculation | Result |
|---|---|---|
| Add 18% GST to ₹1,000 | 1,000 × 18% | GST ₹180 · Total ₹1,180 |
| Remove 18% GST from ₹1,180 | 1,180 ÷ 1.18 | Before GST ₹1,000 · GST ₹180 |
| Add 5% GST to ₹2,000 | 2,000 × 5% | GST ₹100 · Total ₹2,100 |
CGST, SGST and IGST
For a sale within one state, GST is split equally into Central GST and State GST — 18% GST appears on the invoice as 9% CGST plus 9% SGST. For a sale between states, the full rate is charged as Integrated GST (IGST). The total tax is the same either way; only the split changes.
A common mistake
To find the GST inside an inclusive price, don't take 18% of the total. 18% of ₹1,180 is ₹212.40 — too much. The correct GST is ₹180, because the rate was applied to the price before tax. Use "Remove GST" mode, or divide by 1.18.
GST rates for a specific product depend on its HSN or SAC code. Check the official rate schedule or ask your accountant if you're not sure which slab applies.
Frequently asked questions
What are India's current GST rates?
Following the September 2025 GST 2.0 reform, most goods and services fall under two main slabs — 5% and 18% — with a 40% rate reserved for luxury and sin goods like tobacco and pan masala. The older 12% and 28% slabs were folded into 5% and 18%.
What's the difference between "Add GST" and "Remove GST"?
"Add GST" starts from a pre-tax price and calculates the tax-inclusive total. "Remove GST" does the reverse — starting from a price that already includes GST, it works out how much of that total is the base price versus the tax.
Can I use a rate other than the standard slabs?
Yes — type any percentage into the custom rate field and it's used instead of the preset buttons.
Is GST the same in every state?
Yes. GST rates are set nationally by the GST Council, so a product has the same total rate everywhere in India — only the CGST/SGST or IGST split depends on where the buyer and seller are.