GST calculator

How GST is worked out on a bill

Tax is charged on the taxable value — the price of the goods after any discount, before tax. If your price already includes GST, the taxable value is found by taking the tax back out: taxable = amount × 100 ÷ (100 + rate). That is what the "inclusive of GST" setting above does, and it is why an inclusive ₹118 at 18% is ₹100 of goods and ₹18 of tax rather than ₹118 plus ₹21.24.

CGST and SGST, or IGST

Which one you charge depends on where the supply goes, not on where you are.

• Within your own state — the tax splits in half: CGST to the centre and SGST to the state. 18% becomes 9% + 9%.
• To another state — one IGST line at the full rate, no split.

A bill that splits when it should not, or does not split when it should, is wrong on the return as well as on the paper. Aned Book decides it from the customer's state code so the question is never asked twice.

Rounding, and why it is not a detail

Each tax component is rounded to paise on its own line before the lines are added up. Round only at the end and a bill with several lines can be off by a paisa or two against the same bill totalled the other way — which is exactly the kind of difference that costs an afternoon at reconciliation. This calculator rounds in the same order the software does, because it is the software's own code.

The slabs

The rate list above comes from the product, not from a list typed on this page. The GST rates in force are 0%, 0.25%, 3%, 5%, 18% and 40%. If you are looking for 12%, it is no longer a slab.

GST rules change. This page explains how the arithmetic works, and is not tax advice — check the current position with your accountant or the GST portal before you rely on it for a filing.

Questions

Is this GST calculator free?

Yes, and there is nothing to sign up for. It runs entirely in your browser; the amounts you type are never sent to us.

How do I remove GST from an amount?

Set "The amount is" to inclusive of GST. The taxable value is the amount × 100 ÷ (100 + rate) — so ₹1,180 at 18% is ₹1,000 of goods and ₹180 of tax.

When do I charge IGST instead of CGST and SGST?

When the place of supply is a different state from yours. Within your own state the same total tax is split half to CGST and half to SGST.

Is 12% still a GST rate?

No. The rates this calculator offers are the ones in force: 0%, 0.25%, 3%, 5%, 18% and 40%.