GST Calculator
Add India GST to a base price, or back it out from an inclusive price. Splits into CGST and SGST for intra-state invoices.
Mode
GST rate
About India GST
India uses a four-rate GST structure: 5% (essentials), 12% (most services), 18% (standard goods/services), and 28% (luxury & sin goods). On intra-state invoices the total tax splits 50/50 into CGST (Centre) and SGST (State). For inter-state, it's a single IGST line at the full rate — the math is the same.
Remove GST mode treats your input as already including tax and works backwards: base = amount ÷ (1 + rate ÷ 100).
Frequently asked questions
How do I add 18% GST to ₹1,000?
Enter 1000, choose Add GST mode, and select the 18% rate. The tax is ₹180, which splits into CGST ₹90 and SGST ₹90 on an intra-state invoice, giving a total of ₹1,180.
How do I remove GST from a tax-inclusive price?
Switch to Remove GST mode and enter the inclusive amount. The tool works backwards using base = amount ÷ (1 + rate ÷ 100); for example, ₹1,180 at 18% gives a base of ₹1,000 and ₹180 GST.
What's the difference between CGST, SGST, and IGST?
On intra-state sales the GST splits 50/50 into CGST (Centre) and SGST (State) — so 18% becomes 9% + 9%. For inter-state sales it's a single IGST line at the full rate, and the total tax is the same.
Which GST rates does this calculator support?
It supports India's standard slabs — 5%, 12%, 18%, and 28% — plus a Custom field for any other rate, such as 3% on gold.
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