GST Calculator
🔒 In your browserAdd or remove GST, with CGST / SGST split, at any rate.
How it works
Add GST to a price, or pull the GST out of a tax-inclusive amount. Enter the amount and rate, and see the base price, the GST, and the CGST / SGST split.
CGST and SGST are each half the GST for intra-state sales; for inter-state sales the same total is charged as a single IGST.
🔒 Calculated entirely in your browser — nothing is uploaded.
🔒 Calculated in your browser: your loan, investment and salary figures are never uploaded. Interest, tax and salary structures vary by bank and employer, so treat the result as a close estimate and confirm exact figures with them.
About the GST Calculator
This free GST calculator adds GST to a price or extracts it from a tax-inclusive amount. Enter the amount and the GST rate, and it shows the base price, the GST, the CGST / SGST split and the total.
It calculates in your browser — handy for invoices, quotes and quick checks.
Adding vs removing GST
- Add GST — you have a price before tax and want the total. GST = amount × rate ÷ 100, and the total is amount + GST.
- Remove GST — you have a tax-inclusive amount and want the base. Base = amount ÷ (1 + rate ÷ 100), and GST is the difference.
- CGST and SGST are each half the GST for a sale within a state; an inter-state sale charges the same total as a single IGST instead.
A worked example
On a ₹1,000 item at 18% GST, adding tax gives ₹180 GST (₹90 CGST + ₹90 SGST) and a ₹1,180 total. Working backwards from a ₹1,180 inclusive price at 18%, the base is 1,180 ÷ 1.18 = ₹1,000 and the GST is ₹180 — which is why you can't just take 18% of the inclusive amount to find the tax.
Frequently asked questions
How do I add GST to a price?
Multiply the price by the GST rate and divide by 100 to get the GST, then add it. For ₹1,000 at 18%, GST is ₹180 and the total is ₹1,180. The 'add GST' mode does this.
How do I remove GST from a total?
Divide the inclusive amount by (1 + rate ÷ 100). For ₹1,180 at 18%, the base is 1,180 ÷ 1.18 = ₹1,000. The 'remove GST' mode handles it — you can't just subtract 18%.
What are CGST and SGST?
For a sale within a state, GST is split equally into CGST (central) and SGST (state) — each is half the total GST. Inter-state sales use a single IGST of the same total.
What are the common GST rates?
India's GST slabs are 5%, 12%, 18% and 28%, with a few items at 3% or 0%. Pick a slab or enter a custom rate in the calculator.
Is my data uploaded?
No. The calculation runs entirely in your browser.