GST calculator: CGST, SGST or IGST

Work out the GST

Filled in with an example: ₹1,000 including 18% GST, sold within the state.

AmountrupeesUp to two decimal places. Commas are fine. GST rateThe rates of Notification 9/2025-Central Tax (Rate), in force since 22 September 2025.

The amount you typed is

Including GST: take the tax out Before GST: add the tax on

The supply is

Within the state: CGST and SGST Between states: IGST

GST in this amount₹152.54 GST

Taxable value ₹847.46, GST ₹152.54, split equally between CGST and SGST, invoice total ₹1,000.00.

How the GST is worked out, line by line
Line	Working	Amount
Amount you entered	tax included	₹1,000.00
Taxable value	₹1,000.00 × 100 ÷ 118	₹847.46
CGST 9%	₹847.46 × 9%	₹76.27
SGST or UTGST 9%	₹847.46 × 9%	₹76.27
Total GST	CGST + SGST	₹152.54
Invoice total	taxable value + GST	₹1,000.00
Rounding difference	what you entered less the invoice total	₹0.00
Total rounded to the rupee	round-off ₹0.00	₹1,000.00

Raise an order in the demo and it splits the tax the same way, from where the supply goes.Try it with your business name

About this calculator

Type an amount, with or without tax, and pick the rate and where it is sold. You get the taxable value (the price before tax), CGST and SGST or IGST, the invoice total and every rounding step, at the rates in force since 22 September 2025.

A calculator, not tax advice: check the rate for your HSN or SAC code and your place of supply with your CA. Nothing you type leaves this page. Last reviewed 14 October 2026.

How the figures are worked

The rule behind each line.

Including GST. Taxable value = amount × 100 ÷ (100 + rate). At 18%, ₹1,000 holds ₹847.46 of value and ₹152.54 of tax.

Before GST. The amount is the taxable value. Tax goes on top.

Within the state, or between states. Within one state or Union territory: CGST and SGST (UTGST in a Union territory), each at half the rate. Between states: IGST at the full rate. Never both. It depends on where the supplier is and the place of supply, which is usually, but not always, where the buyer takes delivery.

Rounding. Each tax line is rounded half up to the paisa, as on an invoice. So a tax-included amount can come back a paisa off, and CGST plus SGST can differ by a paisa from IGST. The calculator shows that difference. The last line rounds the total to the rupee. Section 170 of the CGST Act rounds tax payable to the rupee; an invoice may carry paise.

The rates. Notification 9/2025-Central Tax (Rate) replaced the goods-rate list from 22 September 2025. 5% and 18% are now the general rates, 40% covers a short list of luxury and demerit goods, and the 12% and 28% general slabs are gone. Special rates did not change: 3% on gold, silver and jewellery, 1.5% on cut and polished diamonds, 0.25% on rough diamonds. See our GST billing guide and HSN codes guide for how the rate follows the code.

What this calculator is not

Three things it leaves to you and your CA.

It does not know your item. The rate depends on the HSN or SAC code. Some items have a rate not listed here, or fall under reverse charge (the buyer pays the tax). Ask your CA.

It does not make an invoice. That also needs supplier and buyer details, GSTIN, HSN code and more.

It sends nothing you type. Nothing is sent, stored or saved on this device; reloading clears it. One count is sent the first time a number you changed gives a result. It names the calculator, not your figures. See the privacy policy.

The rate that applied on the invoice date.

Ordence keeps each HSN's GST rate with the date it started. An old invoice keeps its old rate, and a credit note gets the right one.

Request an invitation More free tools

Questions first? Email the founders.