Free GST Calculator: Add or Remove GST
Add GST to a price or remove it from a GST-inclusive amount in one step. See the base amount, the tax and the split into CGST and SGST or IGST, for any GST rate.
How to use the GST calculator
- Choose Add GST or Remove GST. Add GST when your price is before tax. Remove GST when the amount already includes tax.
- Enter the amount and pick the GST rate.
- Choose the supply type. Within the same state, GST splits equally into CGST and SGST. For another state, it is charged as IGST.
- Read the breakdown and compare the same amount at other common rates.
GST formulas
| To find | Formula | Example at 18% |
|---|---|---|
| GST to add | Amount x rate / 100 | ₹10,000 x 18 / 100 = ₹1,800 |
| Total with GST | Amount + GST | ₹11,800 |
| Base from inclusive price | Total / (1 + rate / 100) | ₹11,800 / 1.18 = ₹10,000 |
| GST inside inclusive price | Total - base | ₹1,800 |
GST rate changes in 2025
From 22 September 2025, the GST Council simplified most goods and services into two main slabs, 5% and 18%, with a 40% rate for certain luxury and sin goods. Some items keep special rates, such as 3% for gold and 0.25% for rough diamonds. Older 12% and 28% slabs are included in the calculator for checking past invoices. Always confirm the current rate for your HSN or SAC code before billing.
CGST, SGST and IGST
If a business in Faridabad, Haryana, sells to a customer in Haryana, the sale is intra-state, so 18% GST becomes 9% CGST and 9% SGST. If the customer is in Delhi, Noida or any other state, it is inter-state and the full 18% is IGST. To create a proper invoice with these splits, use our GST invoice generator.
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Frequently Asked Questions
Is this GST calculator free?
Yes. It is free with no sign-up, and your amounts are calculated in your browser.
How do I remove GST from a price?
Choose Remove GST, enter the GST-inclusive amount and pick the rate. The tool divides by 1 plus the rate to find the base amount and shows the GST inside it.
What are the current GST rates?
Since 22 September 2025, most items fall under 5% or 18%, with 40% for certain luxury and sin goods and a few special rates. Check the rate for your product or service code before billing.
When do I charge IGST instead of CGST and SGST?
Charge IGST when the place of supply is in a different state from your business. Charge CGST plus SGST when it is in the same state.
Is this calculator tax advice?
No. It does the arithmetic only. For rates, exemptions and filing, check with a GST practitioner or chartered accountant.