GST Calculator

What is GST Calculator?

GST, the Goods and Services Tax, is the tax added to most prices in India. This calculator does the two sums people need every day. Add GST works out the tax and the total when you know the price before tax. Remove GST works out the price before tax and the tax when you only know the total. Enter the amount, choose the rate and say whether the sale is within your state or to another state. The result shows the amount without GST, the CGST and SGST (or IGST), the total GST and the total with GST, and each figure has a copy button. Everything is worked out in your browser, so your amounts are never sent anywhere.

How to Calculate GST

1. 1

   Choose Add GST or Remove GST: Use Add GST when you know the price before tax. Use Remove GST when the total already includes tax.

2. 2

   Enter the amount: Type it in rupees. Commas are fine.

3. 3

   Pick the rate: Press a rate such as 18%, or type any other rate in the Other box.

4. 4

   Choose where the sale is: Within your state the tax is split into CGST and SGST. To another state it is charged as IGST.

5. 5

   Copy what you need: Press the copy button next to any figure to paste it into an invoice or sheet.

The GST Formulas

Both sums are simple. The tool rounds each result to the nearest paisa.

• Add GST: GST = amount × rate ÷ 100. Total = amount + GST. For ₹10,000 at 18%, GST is ₹1,800 and the total is ₹11,800.

• Remove GST: Amount without GST = total × 100 ÷ (100 + rate). For ₹11,800 at 18%, the amount without GST is ₹10,000 and the GST is ₹1,800.

• Do not subtract the rate: Taking 18% off ₹11,800 gives ₹9,676, which is wrong. The 18% was added to the smaller price, so it has to be taken out of the larger total with the formula above.

CGST, SGST and IGST

• CGST and SGST: For a sale inside one state, the GST is split in half. One half goes to the central government (CGST) and the other half to the state (SGST). At 18% that is 9% and 9%.

• IGST: For a sale to another state, or an import, the whole GST is charged as IGST. At 18% it is one charge of 18%.

• UTGST: In union territories without their own legislature, UTGST is charged in place of SGST.

• Same total: The total GST is the same either way. Only the way it is split and reported changes.

GST Rates

In September 2025 the GST Council moved most goods and services to two main rates, 5% and 18%, and set 40% for a few luxury and sin goods. The older 12% and 28% rates are kept here because many invoices, returns and old prices still use them. Always check the rate for your own product or service.

• 3%: Gold, silver and some jewellery.

• 5%: Many everyday goods and some services.

• 12% and 28%: Older rates, still needed for earlier invoices.

• 18%: The standard rate for most goods and services.

• 40%: A small group of luxury and sin goods.

Where to Use a GST Calculator

• Invoices and quotes: Show the price, the tax and the total clearly.

• Shop and online pricing: Work out a selling price that includes GST, or the price before GST for your books.

• Checking a bill: Take GST out of a total to see what you actually paid for the goods.

• Freelancers and small businesses: Add GST to your fee before you send the invoice.