Add GST to a base price or remove GST from a GST-inclusive total, at any standard rate — with the CGST and SGST split shown for intrastate supply.
Quick answer: To add 18% GST, multiply the price by 1.18; to remove it, divide the total by 1.18. On ₹1,000 the GST is ₹180, split as ₹90 CGST + ₹90 SGST.
For supply within a state, GST splits equally into CGST and SGST. For interstate supply the same total is charged as a single IGST. Choose "Add GST" when your price excludes tax, or "Remove GST" to back the tax out of a tax-inclusive total.
Goods and Services Tax (GST) in India applies at slab rates of 5%, 12%, 18% and 28% (with 3% on gold and 0.25% on rough gems). This calculator does both jobs: it adds GST to a pre-tax price to give the amount payable, and removes GST from a tax-inclusive total to reveal the base value and the tax within it. Outside India, use our New Zealand GST, Singapore GST or Ireland VAT calculator for those countries' rates.
How to add and remove GST
Add: GST = amount × rate% · total = amount + GST Remove: base = total ÷ (1 + rate%) · GST = total − base
Base ₹1,000 + GST
GST
Total
5%
₹50
₹1,050
12%
₹120
₹1,120
18%
₹180
₹1,180
28%
₹280
₹1,280
Worked example
A bill shows ₹1,180 including 18% GST. Removing GST: base = 1,180 ÷ 1.18 = ₹1,000, so the GST is ₹180 (₹90 CGST + ₹90 SGST).
CGST, SGST and IGST
Within a state, GST is levied half as Central GST (CGST) and half as State GST (SGST) — so 18% is 9% + 9%. For sales between states the whole amount is charged as Integrated GST (IGST) instead. The total tax is the same either way; only the split differs.
Frequently asked questions
How do I remove GST from a total?
Divide the total by 1 plus the rate — e.g. for 18%, divide by 1.18. The result is the base; the rest is GST.
What are the GST slab rates?
0%, 5%, 12%, 18% and 28%, plus special rates of 3% on gold and 0.25% on rough diamonds.
How is GST split into CGST and SGST?
Equally — an 18% intrastate GST is 9% CGST and 9% SGST. Interstate supply uses a single IGST instead.
Is GST added on the base or the total?
On the base (pre-tax) price. To find the base from a tax-inclusive total, use the "Remove GST" option.
How do I add GST to a price?
Multiply the price by the rate and add it on — for 18%, GST = price × 0.18 and the total is price × 1.18. Use the "Add GST" option above to do it automatically.
What is the formula for GST calculation?
To add GST: total = amount × (1 + rate). To remove GST: base = total ÷ (1 + rate). The GST amount is the difference between the total and the base.
