GST Calculator
Calculate GST Inclusive & Exclusive Amounts
Add GST to a price or remove GST from a price — instantly see the CGST, SGST, IGST breakup and final amount for any GST rate in India.
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How to Calculate GST
GST (Goods and Services Tax) can be calculated in two directions. To add GST to a base price: GST amount = base price × (rate / 100), and total = base price + GST amount. To remove GST from a price that already includes it: base price = total ÷ (1 + rate / 100), and GST amount = total − base price.
GST Amount = (Original Cost × GST Rate) / 100
For sales within the same state (intra-state), GST is split equally into CGST (Central GST) and SGST (State GST) — each being half the total GST rate. For sales between different states (inter-state), the full amount is charged as IGST (Integrated GST) instead.
Common GST slabs in India are 5%, 12%, 18% and 28%, though this calculator also accepts any custom rate.
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CGST (Central GST) and SGST (State GST) apply together on sales within the same state, each charged at half the total GST rate. IGST (Integrated GST) applies on sales between two different states, charged at the full GST rate and collected by the central government, which then settles it with the states involved.
Divide the total amount by (1 + GST rate/100) to get the base price, then subtract the base price from the total to get the GST amount. For example, for a ₹1180 price including 18% GST, the base price is 1180 ÷ 1.18 = ₹1000, and the GST amount is ₹180.
The most common GST slabs are 5%, 12%, 18% and 28%, with some essential goods at 0% and certain luxury or sin goods attracting an additional cess on top of 28%. The applicable rate depends on the specific goods or services category under the HSN/SAC code.
Yes — this same add/remove GST logic is exactly what's tested in Accountancy and Business Studies board exam numericals and in TNPSC/competitive exam GST questions. Check the step-by-step section after calculating to see the full method, not just the final figure.