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GST calculator

CGST / SGST / IGST split

Enter an amount and a GST rate to add GST or take it out of a GST-inclusive price, with the CGST and SGST halves (or IGST for inter-state supply). Pick 'Other rate' for VAT or sales tax.

Try:

Fill in the fields to see the result.

How to use it

  1. Enter the amount and choose the GST rate.
  2. Choose whether the amount is before tax or already includes it.
  3. Read the tax, net and gross amounts and the CGST/SGST split; copy or download the result.

Details

Add GST
Gross = net × (1 + rate)
Remove GST
Net = gross ÷ (1 + rate); GST = gross − net
Split
Intra-state: CGST and SGST each half the rate. Inter-state: IGST at the full rate
Rates
5% and 18% main slabs, 40% special rate, 3% gold, 0.25% rough diamonds, 0% exempt

Questions

How do I remove GST from a price?

Divide the inclusive price by 1 plus the rate. At 18%, ₹1,180 ÷ 1.18 = ₹1,000 before tax, so the GST is ₹180. Choose 'Including tax' and the calculator does this.

Why isn't the GST on an inclusive price just 18% of it?

Because 18% of ₹1,180 is ₹212.40, which counts tax on the tax. The correct GST share of an inclusive price at 18% is 18/118 of it.

When is IGST charged instead of CGST and SGST?

On inter-state supplies (seller and place of supply in different states) and imports. Within one state, the rate is split equally into CGST and SGST (or UTGST).

Which GST rate applies to my product?

It depends on the HSN or SAC code. After the 2025 rationalisation most goods are at 5% or 18%; check the CBIC rate notification for your code.

Can I use it for VAT or US sales tax?

Yes. Pick 'Other rate', type the rate (for example 20% UK VAT) and choose the currency. The split is shown only for GST.

Is what I type sent anywhere?

No. The calculation runs in this browser tab with the same code our MCP server uses. Nothing you type is sent to a server or saved, apart from settings like filing status, which stay in this browser.

Can an AI agent use this?

Yes. The same function is a tool on our free MCP server at tools.cuelark.com/mcp, so ChatGPT, Claude or Cursor get exactly the answer this page shows. 'Copy MCP call' gives you the arguments.