GST Calculator
Add or remove GST at any rate and see the exact CGST + SGST (intra-state) or IGST (inter-state) split. Free, runs entirely in your browser.
- Runs in your browser
- Free login required
- Always free
How GST is calculated
GST is charged as a percentage of the taxable value. To add GST, multiply the taxable amount by the rate; the gross is taxable + GST. To remove GST from a gross (inclusive) price, divide by (1 + rate/100) to recover the taxable value, then the GST is the difference.
Within a state (intra-state), GST splits equally into CGST and SGST, each at half the rate. Across states (inter-state), a single IGST applies at the full rate. This calculator rounds each tax to the paise exactly the way the Quillix billing engine does.
Working out GST on real invoices?
This calculator splits one amount. Raise a GST tax invoice in Quillix computes the CGST plus SGST or IGST split per line from the customer place of supply, so the return is built from the books rather than re-keyed.
GST calculator — FAQ
How do I remove GST from an inclusive amount?
Switch the mode to "Remove GST", enter the gross (tax-inclusive) amount and pick the rate. The calculator divides by (1 + rate/100) to recover the taxable value and shows the GST that was embedded in the price.
What is the difference between CGST, SGST and IGST?
For a supply within the same state, GST is split into CGST (central) and SGST (state), each at half the rate. For a supply between two different states, a single IGST applies at the full rate. Choose "Intra-state" or "Inter-state" to see the right split.
Which GST rates can I use?
The common slabs are 0%, 5%, 12%, 18% and 28%. Use the "Custom %" box for any other rate, including decimals such as 0.25% or 1.5%.
Is this GST calculator free?
Yes — it is completely free once you log in (no cost to sign up), and runs entirely in your browser. Nothing you type is sent anywhere.
