GST Calculator

Overview

Calculate GST (Goods and Services Tax) quickly — add GST to a base amount, or work out how much of a GST-inclusive amount is tax. Includes the standard Indian GST slabs (5%, 12%, 18%, 28%) and a CGST/SGST vs. IGST breakdown.

GST Formulas

Add GST (exclusive amount → total):

GST Amount = Base Amount × (GST Rate / 100)
Total Amount = Base Amount + GST Amount

Remove GST (inclusive amount → base):

Base Amount = Total Amount / (1 + GST Rate / 100)
GST Amount = Total Amount − Base Amount

CGST, SGST, and IGST

For a transaction within the same state, GST is split equally between Central GST (CGST) and State GST (SGST) — each is half the total GST rate. For an inter-state transaction, the full amount is charged as Integrated GST (IGST) instead.

How to use this calculator

1. Choose whether you're adding GST to a base amount or extracting GST from a total.
2. Enter the amount and pick a GST rate (or enter a custom rate).
3. Choose same-state or inter-state to see the CGST+SGST or IGST breakdown.