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GST & tax

GST Calculator

Add or remove GST at 5%, 18% or 40%, with the CGST/SGST or IGST split.

AInputsExample numbers. Type over them.
₹
1 lakh
The amount is
Supply
BResultsClick a row to see its formula
B3fx= ₹1,00,000.00 + ₹18,000.00
1Taxable value₹1,00,000.00
2GST @ 18%₹18,000.00
3Total (invoice value)₹1,18,000.00
4CGST @ 9%₹9,000.00
5SGST @ 9%₹9,000.00
ScenariosSaved in this browser only

How this calculator works

Use this to add GST to a price before you raise an invoice, or to pull the GST out of an amount that already includes it. It also splits the tax into CGST and SGST for sales within your state, or shows it as IGST for sales to another state.

Since GST 2.0 took effect on 22 September 2025, most goods and services sit at 5% or 18%, with 40% for luxury and sin goods and 0% for essentials. Old 12% and 28% items have mostly moved into these slabs, so check the current rate for your HSN or SAC code.

Formula

Adding GST: GST = amount × rate ÷ 100 Total = amount + GST Removing GST: Taxable value = amount × 100 ÷ (100 + rate) GST = amount − taxable value Same state: CGST = SGST = GST ÷ 2 Other state: IGST = GST

Worked example

A Gurugram trader sells goods worth ₹1,00,000 to a buyer in Haryana at 18%. GST is ₹18,000, split into ₹9,000 CGST and ₹9,000 SGST, and the invoice total is ₹1,18,000. If the same buyer were in Rajasthan, the full ₹18,000 would be charged as IGST.

Things to watch

  • Removing GST is not the same as taking 18% off. ₹1,18,000 less 18% is ₹96,760, but the correct taxable value is ₹1,00,000.
  • Place of supply decides CGST + SGST versus IGST, not where your office is.
  • Round GST on the invoice to the nearest rupee only at the total level, not line by line, to avoid mismatches in GSTR-1.

Questions

What are the GST slabs now?

After GST 2.0 (22 September 2025) the main slabs are 5% and 18%, a 40% rate for luxury and sin goods, and 0% for nil-rated essentials. A few items such as gold keep special rates like 3%.

How do I calculate GST from an inclusive price?

Divide the inclusive amount by (100 + rate) and multiply by 100 to get the taxable value. The difference is the GST. At 18%, ₹1,180 inclusive is ₹1,000 plus ₹180 GST.

When do I charge IGST instead of CGST and SGST?

When the supplier and the place of supply are in different states or union territories. Within the same state you charge CGST and SGST in equal halves.

Do I need GST registration to charge GST?

Yes. Only registered businesses can charge GST. Service providers must register once aggregate turnover crosses ₹20 lakh a year (₹10 lakh in special category states).

For planning and education only, not tax, legal or investment advice. Last reviewed 2026-10-31.