India tax utility
GST Calculator India – Add or Remove GST
Calculate inclusive or exclusive GST and split the tax into CGST and SGST or IGST.
Calculate GST
GST formulas
Add GST: GST = base amount × rate ÷ 100. Total = base amount + GST.
Reverse GST: base amount = inclusive amount ÷ (1 + rate ÷ 100). GST = inclusive amount − base amount.
For an intra-state estimate, the calculator divides the GST equally into CGST and SGST. For inter-state mode, it shows the tax as IGST.
Worked example: reverse 18% GST
For a GST-inclusive price of ₹1,180 at 18%, the base value is ₹1,000 and the GST is ₹180. In intra-state mode, the estimate displays ₹90 CGST and ₹90 SGST.
Actual classification, exemptions, place-of-supply rules, and filing treatment can differ. Check the applicable GST Council rate notifications.
Limitations
This calculator is an arithmetic aid, not tax or filing advice. It does not determine HSN/SAC classification, input-tax-credit eligibility, reverse charge, cess, exemptions, or the legally applicable rate.
Reviewed: 26 July 2026 · Source checked against GST Council rate notifications · Editorial policy
Frequently asked questions
How do I remove GST from an inclusive price?
Choose Remove GST, enter the final GST-inclusive amount, and select the applicable rate. The calculator separates the base value and tax.
What is the difference between CGST, SGST, and IGST?
For an intra-state supply, GST is generally split equally between CGST and SGST. For an inter-state supply, the tax is shown as IGST.
Can I use this result for filing a GST return?
Use it as an estimate only. Confirm the applicable classification, place of supply, rate, and filing treatment with official guidance or a qualified tax professional.
What this calculator estimates
This calculator separates a taxable value from GST or adds GST to a pre-tax amount. Choose the transaction type and applicable rate before using the result.
Methodology and assumptions
For an exclusive amount, GST is the taxable value multiplied by the selected rate. For an inclusive amount, the taxable value is the gross amount divided by one plus the rate. Intra-state tax is displayed as equal CGST and SGST shares; inter-state tax is displayed as IGST.
Authoritative sources
- Search HSN/SAC tax rates and GST Portal disclaimerGoods and Services Tax Network
Sources checked September 1, 2026. Regulations and guidance can change; use the linked authority for the current position.
Related tools
Methodology, sources, and limitations reviewed: September 1, 2026. The calculation engine and displayed assumptions are reviewed together; report a mismatch through the corrections policy.