GST calculator
A GST calculator adds or removes Goods and Services Tax from an amount. To add GST, multiply the base by the rate – 18% GST on ₹1,000 is ₹180, giving ₹1,180. To remove GST from a tax-inclusive total, divide by 1 plus the rate. This free tool handles both, splits the tax into CGST and SGST, and works for the 5%, 12%, 18% and 28% slabs or any custom rate.
Calculate GST
Nothing is stored – the calculation runs in your browser.
For intra-state supply GST splits equally into CGST and SGST. Inter-state supply is charged as a single IGST of the same total rate.
How to calculate GST
- Enter the amount – the base amount to add GST to, or the GST-inclusive total to break down.
- Pick add or remove GST depending on whether your amount excludes or includes tax.
- Choose the GST rate – 5%, 12%, 18%, 28% or a custom rate.
- Read the result – base, GST, total and the CGST/SGST split.
GST rates in India
| GST slab | Typically applies to |
|---|---|
| 0% | Essential and exempt goods (fresh produce, certain food grains) |
| 5% | Household essentials, transport, small restaurants |
| 12% | Processed foods, business-class travel, some apparel |
| 18% | Most services and goods (the most common slab) |
| 28% | Luxury and "sin" goods, premium vehicles, tobacco |
Slabs are set by the GST Council and can change. Use the custom-rate option for special rates or cess. Check the latest notification for the exact rate on a specific HSN/SAC code.
Worked example
Suppose a service costs ₹1,000 before tax at 18% GST. The GST is ₹1,000 × 18% = ₹180, so the customer pays ₹1,180. Within the same state that ₹180 is split into ₹90 CGST and ₹90 SGST. To reverse it: from a ₹1,180 inclusive total, the base is ₹1,180 / 1.18 = ₹1,000 and the GST is ₹180.
Frequently asked questions
How do I calculate GST on an amount?
To add GST, multiply the base amount by the GST rate and add it to the base. For example, 18% GST on Rs 1,000 is Rs 180, so the total is Rs 1,180. To remove GST from a GST-inclusive price, divide the total by 1 plus the rate: Rs 1,180 / 1.18 = Rs 1,000 base and Rs 180 GST.
What are the GST rates in India?
GST in India has four main slabs - 5%, 12%, 18% and 28% - plus 0% for exempt goods. 18% is the most common rate and applies to most services and many goods. The calculator lets you pick a slab or enter a custom rate.
What is the difference between CGST and SGST?
For sales within the same state, GST is split equally into CGST (central) and SGST (state). So 18% GST is 9% CGST plus 9% SGST. For inter-state sales, the same total is charged as a single IGST instead.
How do I remove GST from a total (reverse GST)?
Choose 'Remove GST' in the calculator and enter the GST-inclusive amount. It divides by 1 plus the rate to recover the base amount and shows how much of the total was GST.
Is this GST calculator free?
Yes. It is completely free, needs no sign-up, and runs entirely in your browser - the figures you enter are not sent to or stored on any server.
