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.
Rate presets and effective dates
The 5% merit rate and 18% standard rate generally took effect for notified goods and services on 22 September 2025. The 40% demerit rate applies only to specifically notified classifications; the revised 40% treatment for specified pan masala, tobacco, cigarette, and nicotine-inhalation products took effect on 1 February 2026.
The 12% and 28% presets remain available because some notified schedules and transitional or item-specific classifications can still require them. A preset is arithmetic only: verify the current HSN/SAC entry and effective notification before invoicing.
Sources: GST Council rate notifications and CBIC goods and services rates.
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.
Official source last checked: 11 September 2026 · GST Council and CBIC 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.