FINBIZTOOLS
GST Calculator
Add or remove GST from an amount and estimate CGST, SGST or UTGST, and IGST using a rate you select.
Private by design · Your inputs stay in this browser
How to use the GST calculator
Enter an amount and select a GST rate or enter a custom percentage. Choose Exclusive to add GST to a base price, or Inclusive to extract GST from a tax-inclusive total. Select the applicable supply type to display either CGST plus SGST / UTGST or IGST.
Methodology
Exclusive: GST = base × rate ÷ 100; final = base + GST. Inclusive: base = final ÷ (1 + rate ÷ 100); GST = final − base. For the intra-state illustration, tax is split equally between CGST and SGST / UTGST. For the inter-state illustration, the entire tax is shown as IGST. These components are alternatives and are not added together.
Example
At an illustrative rate of 18%, a ₹1,000 exclusive amount produces ₹180 GST and ₹1,180 total. An inclusive amount of ₹1,180 produces ₹1,000 base and ₹180 GST. The intra-state split is ₹90 CGST and ₹90 SGST / UTGST.
Rates and transaction treatment
The selectable 0%, 5%, 12%, 18% and 28% are arithmetic presets, not a current classification or a recommendation. Use Custom for another percentage. Verify the applicable notified rate, place of supply, exemptions and tax treatment for your specific transaction. This tool does not determine liability, input tax credit, reverse charge, cess, special valuation or invoice-level rounding.
Supported inputs
Amount: ₹0 to ₹100 crore; rate: 0% to 100%. Decimals and zero-rated arithmetic are supported. Displayed amounts are rounded to two decimal places. Independently rounded components can differ by one paisa from a displayed total.
Background: CBIC introduction to GST. Check official notifications and professional advice for current treatment.
Frequently asked questions
Does this choose the correct GST rate?
No. You must select a verified rate applicable to your transaction.
Should I use IGST or CGST and SGST?
The relevant place-of-supply and tax rules determine the treatment. Select the applicable type after verification; this calculator only illustrates the split.
Can I calculate a custom rate?
Yes. Select Custom and enter a percentage from 0 to 100.
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Disclaimer
This calculator provides informational estimates, not financial, investment, lending or tax advice. Verify important decisions with a qualified professional. No financial outcome is guaranteed. Read our Disclaimer.
Create business documents
Use the GST Invoice Generator or Quotation Generator for itemized documents. Verify tax treatment before issuing.