Add GST to an amount or work backwards from a GST-inclusive total, with the CGST and SGST split shown for intra-state supply.
Runs in your browser — nothing is uploaded
CGST ₹900 + SGST ₹900 for intra-state
Add GST or extract it from an inclusive figure — the usual source of invoice errors.
Shows the halves you need for an intra-state invoice.
Everything runs in your browser, so your input never reaches a server.
No account, no usage cap, and no feature held back behind a paywall.
Enter the amount.
Pick the GST slab — 0, 3, 5, 12, 18 or 28%.
Say whether the amount already includes GST.
Adding 18% to ₹1,000 gives ₹1,180. But extracting 18% GST from ₹1,180 does not mean subtracting 18% of ₹1,180 — that gives ₹967.60, which is wrong. You divide by 1.18 to get back to ₹1,000.
This asymmetry is behind a large share of invoice mistakes. The calculator asks which case you are in rather than guessing.
For supply within a state, GST splits evenly into CGST (central) and SGST (state) — 18% becomes 9% plus 9%. For supply between states, the whole amount is IGST instead.
The total is identical either way; only the split and the return you file differ. The tool shows the intra-state halves, since that is the more common invoicing case.
Available tools are linked; the rest are in development.
We build internal tools, dashboards and automation that fit how your team works.