GST Calculation in India: Inclusive vs Exclusive
Updated 12 August 2026 · 5 min read
How to add GST, remove GST from an inclusive price and split it into CGST, SGST or IGST.
Adding GST
GST amount = Base price × Rate ÷ 100. Final price = Base price + GST. Example: ₹1,000 at 18% → ₹180 GST → ₹1,180.
Removing GST from an inclusive price
Base price = Inclusive price × 100 ÷ (100 + Rate). Example: ₹1,180 inclusive at 18% → base ₹1,000, GST ₹180.
CGST, SGST and IGST
For sales within a state, the tax is split equally into CGST and SGST (9% + 9% for 18%). For inter-state sales, the full rate is charged as IGST.