How to use it
Type the amount, choose the GST rate, and pick whether the amount is before GST (to add GST) or including GST (to find the price before GST).
The formulas
- Adding GST: GST = Amount × rate ÷ 100, total = amount + GST
- Removing GST: Amount before GST = Total ÷ (1 + rate ÷ 100)
On a sale within a state the tax is split equally into CGST and SGST; on a sale to another state it is charged as IGST.
GST rates after GST 2.0
From 22 September 2025 most goods and services fall in two main slabs, 5% and 18%, with a 40% rate for a small set of luxury and sin goods; some items carry special rates (for example 3% on gold) or are exempt. Always check the rate for your specific goods or service with your accountant or the official notifications.
For business owners
Regular GST filing is one of the clearest proofs of turnover when you apply for a business loan. Read who needs GST registration.