Goods and Services Tax is charged as a percentage on top of the base price, and the tricky everyday cases are working backwards from a tax-inclusive bill and splitting the tax correctly on an invoice. Enter an amount, pick the rate (5%, 12%, 18%, 28%, the special 3% and 0.25% rates, or a custom figure) and choose whether to add or remove GST. The calculator shows the base price, the tax and the total, split into CGST and SGST for supplies within a state or shown as IGST for supplies between states.
GST Calculator
Goods and Services Tax is charged on top of the base price at 5%, 12%, 18% or 28%, with special rates of 3% and 0.25% for jewellery and diamonds and a list of exempt items at 0%. The GST calculator adds the tax to an exclusive price or strips it out of an inclusive one, which is the everyday problem when an invoice shows only the total. A ₹10,000 service at 18% becomes ₹11,800; a ₹11,800 bill at 18% contains ₹1,800 of tax on a ₹10,000 base.
How the tax is split depends on where buyer and seller are. For a supply within one state the amount is divided equally into CGST (to the centre) and SGST or UTGST (to the state or union territory), so 18% appears as 9% + 9% on the invoice; for a supply between states the whole amount is IGST. The calculator shows the right split for both cases. Use the custom-rate field for compensation cess or any rate not in the list, and check the current schedule for your product on the GST portal before invoicing.
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Frequently Asked Questions
How do I remove GST from a price?
Divide the inclusive price by 1 plus the rate: ₹11,800 ÷ 1.18 = ₹10,000, so the GST was ₹1,800. Choose the 'remove GST' mode to do this automatically.
What is the difference between CGST, SGST and IGST?
Within one state the tax is split equally between the central government (CGST) and the state (SGST, or UTGST in a union territory). For supplies between states the whole tax is IGST, collected by the centre. The total is the same either way.
Which GST rate applies to my product?
Rates are set by HSN or SAC code and change from time to time; the 2025 rationalisation moved many items between slabs. Check the current schedule on the GST portal for your specific code before invoicing.
