GST Calculator
Enter an amount and a GST rate, and choose whether the amount is before or including GST. You get the GST, the total or base price, and the CGST, SGST and IGST split.
Check the rate for your item or service on the GST portal. Most rates are now 5%, 18% or 40%.
Total with GST
₹11,800
GST ₹1,800
- Price before GST
- ₹10,000
- GST amount
- ₹1,800
- CGST + SGST (each half)
- ₹900 + ₹900
- IGST (inter-state)
- ₹1,800
Saved results stay in this browser only. Clearing your browser data removes them.
- Within a state GST is split equally into CGST and SGST. Between states it is charged as IGST. Rates changed from 22 September 2025, so confirm the rate for what you sell.
Adding and removing GST
To add GST, multiply the price by the rate and add it. To remove GST from an inclusive price, divide by 1 plus the rate. Subtracting the percentage from the total gives a wrong answer, which is a common mistake.
For a sale within one state, GST is split equally into CGST and SGST. For a sale between states it is charged as IGST, for the full amount.
GST rates were restructured from 22 September 2025, and most goods and services now fall under 5%, 18% or 40%. Check the rate for your item or service on the GST portal before invoicing.
The formula
GST = price before GST × rate ÷ 100. Price before GST = inclusive price ÷ (1 + rate ÷ 100). CGST = SGST = GST ÷ 2.
Common questions
How do I calculate GST on a price?
Multiply the price before GST by the rate and add it. For ₹10,000 at 18%, GST is ₹1,800 and the total is ₹11,800.
How do I remove GST from an inclusive price?
Divide the inclusive price by 1 plus the rate. ₹11,800 at 18% gives ₹10,000, so GST is ₹1,800.
When is it CGST and SGST, and when IGST?
CGST and SGST apply when the supplier and the place of supply are in the same state. IGST applies between states.
Which GST rate applies to my product?
It depends on what you sell. Look it up on the GST portal or ask your accountant, because rates are set per item and service.
Invoice with GST in one place
SparkyInvoices handles GST-compliant invoicing for small businesses: draft, send and track invoices, with the tax worked out for you.
Try SparkyInvoices (opens in a new tab)