GST Calculator
Add GST to a base price or remove GST from a total. Covers the current Indian GST slabs (0%, 5%, 18% and 40%) with a CGST/SGST breakdown. Runs entirely in your browser.
Which calculation do you need?
Add GST when you have a base price. Exclude GST when you have a total and need to find what's inside it.
How to calculate GST
Pick Add or Remove, then enter the amount and the slab.
- 01
Pick Add GST or Remove GST
Add GST starts from a price before tax and gives the total. Remove GST starts from a tax-inclusive total, such as an MRP or a receipt, and finds the price before tax.
- 02
Choose intra-state or inter-state
Within one state the tax is split equally into CGST and SGST. Across states it's shown as a single IGST amount. The total tax is the same either way.
- 03
Enter the amount and rate, or several line items
Both calculators have a single-amount mode and a multi-item mode, where each line can carry its own rate. That's the mode to use for a bill that mixes 5% and 18% goods.
CGST, SGST, IGST and the 2025 slab change
Within one state, GST is split equally into CGST (central) and SGST (state): an 18% item carries 9% of each. When the buyer is in another state, the whole amount is charged as IGST instead. The total is the same either way; what changes is which government receives it and how it appears on the invoice.
From 22 September 2025, the GST Council moved most goods and services to two main slabs, 5% and 18%, with a 40% rate for luxury and sin goods. Most items that were at 12% dropped to 5%, and most at 28%, such as ACs, large TVs and cement, dropped to 18%. Check an older invoice against the rate in force on its date before reusing its numbers.
The four slabs at a glance
This table works both ways. The multiplier turns a pre-tax price into the total. The last numeric column tells you what share of a tax-inclusive price is GST, which is the figure people most often get wrong.
| Rate | Multiply the base by | GST on a ₹1,000 base | GST share of an inclusive price | Typical items |
|---|---|---|---|---|
| 0% | 1.00 | ₹0 | 0% | Fresh food, milk, books, many health and education services |
| 5% | 1.05 | ₹50 | 4.76% | Most daily essentials, many foods, medicines |
| 18% | 1.18 | ₹180 | 15.25% | Standard rate: most services, electronics, appliances |
| 40% | 1.40 | ₹400 | 28.57% | Luxury and sin goods: large cars, tobacco, aerated drinks |
So ₹1,180 including 18% GST is ₹1,000 plus ₹180 of tax, and the tax is 15.25% of the total, not 18%. Taking 18% off ₹1,180 gives ₹967.60, which understates the base by ₹32.40. The examples of items per slab are a general guide; the rate for a specific product depends on its HSN or SAC code.
What the calculators don't handle
- Compensation cess and other levies aren't included. Add them separately if they still apply to your goods.
- Rounding to the rupee isn't applied. Amounts show to two decimal places; invoices usually round the final total to the nearest rupee.
- Classification isn't checked. The tool applies the rate you pick, so confirm the right slab for your HSN or SAC code with your accountant.
- Reverse charge, composition scheme rates and exemptions for specific buyers need professional advice rather than a calculator.
Frequently asked questions
The complete guide to GST calculations
Forward and reverse GST formulas, CGST, SGST and IGST, and rounding on invoices.