GST calculator
Add GST to a price or take it out of a price that already includes it, and see the CGST and SGST (or IGST) split — free, no sign-up.
Make GST bills without working it out
The Ray adds the right GST, prints the split on every bill, and makes GSTR-1 and GSTR-3B from them. Free 14-day trial.
How GST is calculated
Adding GST: GST = price × rate ÷ 100, and total = price + GST.
Removing GST: price before GST = total ÷ (1 + rate ÷ 100), and GST = total − price before GST.
Splitting it: within your state, half is CGST and half SGST; to another state, all of it is IGST.
Questions
How do I add GST to a price?
Multiply the price by the GST rate and divide by 100; that is the GST. Add it to the price for the total. For ₹1,000 at 18%: GST = 1,000 × 18 ÷ 100 = ₹180, total ₹1,180.
How do I remove GST from a price that includes it?
Divide the inclusive price by (1 + rate ÷ 100) to get the price before GST; the rest is GST. For ₹1,180 at 18%: 1,180 ÷ 1.18 = ₹1,000 before GST, so GST is ₹180.
When is it CGST + SGST and when is it IGST?
A sale within your own state carries CGST and SGST, each half of the rate (18% = 9% CGST + 9% SGST). A sale to a buyer in another state carries the whole rate as IGST.
What are the GST rates now?
From 22 September 2025 most goods and services fall under 5% or 18%, with 40% for a small list of luxury and sin goods; some items are exempt (0%) and gold and jewellery are at 3%. Rates depend on the item's HSN or SAC code, so check yours — the calculator also takes any other rate.
Does my bill need to show the GST split?
A GST invoice shows the taxable value and the CGST and SGST (or IGST) amounts with their rates. Billing software such as The Ray works this out and prints it on every bill for you.