GST Calculator (India) Online
Add or remove Indian GST at 0%, 5%, 12%, 18% or 28% and compare base, tax and total amounts.
Method and limitations reviewed August 3, 2026. Browser-first, no login required.
Base amount
₹ 1,000
GST amount
₹ 180
Total
₹ 1,180
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About this tool
What this tool does
The GST calculator separates base amount, GST amount and gross total for quick invoice checks. It supports adding tax to a base price and extracting the included tax from a tax-inclusive price.
How the result is produced
- Add GST multiplies the entered amount by the selected rate and adds the tax to the base amount.
- Remove GST divides the inclusive amount by 1 plus the GST rate expressed as a decimal.
- The included GST component is the difference between the inclusive amount and the calculated base amount.
- Preset buttons cover 0%, 5%, 12%, 18% and 28%; the result uses the exact rate shown in the input.
Good uses
- Checking a tax-inclusive supplier quote
- Estimating GST before preparing an invoice
- Comparing base and gross prices at different rates
How to verify the result
- Confirm the applicable GST rate from an official source or your tax adviser.
- Check whether your document needs CGST and SGST or IGST presentation.
- Apply your accounting system's rounding rule before filing or posting entries.
Known limitations
- The calculator does not decide which GST rate applies to a product or service.
- It does not determine place of supply, input tax credit, exemptions or filing treatment.
- Results are estimates and are not tax advice or a compliance certificate.