GST & VAT Calculator: add or remove GST (5%, 18%, 40%)

Add GST to a price or take it out of a GST-inclusive amount, and see the CGST/SGST or IGST split for your invoice.

How to use the GST calculator

Choose Add GST if your amount excludes tax, or Remove GST if it already includes tax.
Enter the amount and pick a GST rate (or type any rate).
Choose Within state for CGST + SGST or Other state for IGST.

GST formulas

Add GST: GST = amount × rate ÷ 100, total = amount + GST
Remove GST: base = amount × 100 ÷ (100 + rate), GST = amount − base
Intra-state: CGST = SGST = GST ÷ 2. Inter-state: IGST = GST

Worked example

A Chennai seller bills a Chennai customer ₹25,000 for a service taxed at 18%. GST is ₹4,500, split into ₹2,250 CGST and ₹2,250 SGST, and the invoice total is ₹29,500. If the customer were in Bengaluru, the same ₹4,500 would be charged as IGST.

Using it as a VAT calculator

VAT is added and removed with exactly the same maths, so you can use this page for VAT anywhere: type your country's VAT rate in the GST rate box, choose Add GST or Remove GST, and read the base, tax and total. Ignore the CGST/SGST and IGST lines, which only apply to GST in India. For example, removing a 20% tax from 120 gives a base of 120 × 100 ÷ 120 = 100 and tax of 20.

Frequently asked questions

What are the current GST rates in India?

Since 22 September 2025 (GST 2.0), the main slabs are 0%, 5%, 18% and 40%. The 12% and 28% slabs were largely removed. Special rates such as 3% (gold and jewellery) and 0.25% (rough diamonds) also apply. Always check the rate for your specific HSN/SAC code.

How do I add GST to a price?

GST amount = price × rate ÷ 100, and total = price + GST amount. For example, ₹1,000 at 18% gives ₹180 GST and ₹1,180 total.

How do I remove GST from an inclusive price?

Base price = inclusive amount × 100 ÷ (100 + rate). For example, ₹1,180 including 18% GST has a base price of ₹1,000 and GST of ₹180.

When is it CGST + SGST and when is it IGST?

If the supplier and the place of supply are in the same state (intra-state), the GST is split equally into CGST and SGST (or UTGST). If they are in different states (inter-state), the full amount is charged as IGST.

GST Calculator