GST calculator
Add GST to a price, or find how much GST is inside a GST-inclusive amount, with the CGST and SGST or IGST split.
Rupees one thousand one hundred eighty only
Making the invoice too? SmartRaseed does this maths on every GST invoice.
The GST formulas
Adding GST: GST = price × rate ÷ 100. Total = price + GST.
Removing GST: GST = total × rate ÷ (100 + rate). Price before GST = total − GST.
A common mistake is taking 18% of a GST-inclusive ₹1,180, which gives ₹212.40 instead of the correct ₹180. Always divide by 100 plus the rate.
Worked examples and rounding rules are in how to calculate GST.
Questions and answers
How do I calculate GST on a price?
Multiply the price by the rate and divide by 100. For ₹1,000 at 18%: 1,000 × 18 ÷ 100 = ₹180, so the total is ₹1,180.
How do I remove GST from a GST-inclusive price?
GST = total × rate ÷ (100 + rate). For ₹1,180 at 18%: 1,180 × 18 ÷ 118 = ₹180, so the price before GST is ₹1,000.
When do I charge CGST and SGST, and when IGST?
CGST and SGST (half the rate each) apply when the place of supply is in your own state. IGST at the full rate applies when it's in another state.
What are the GST rates now?
Since 22 September 2025 most goods and services are taxed at 5% or 18%, with 40% for a short list of luxury and sin goods. Some items are exempt, and a few have special rates such as 3% on gold and 0.25% on rough diamonds.
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