GST calculator for India: add or remove GST
Enter an amount, say whether GST is in it, pick the rate and see the GST, the taxable value, the total and how the tax splits between the central and state governments.
Results
GST
0.00
The whole GST on the supply, before it is split.
- GST
- 0.00
- Taxable value
- 0.00
- Total with GST
- 0.00
- CGST
- 0.00
- SGST
- 0.00
- Summary
- -
| Rate | Taxable value | GST | Total |
|---|
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For information only, not financial, tax or legal advice.
Last updated . Method checked . Methodology
Goods and Services Tax in India has two main rates since September 2025, 5% and 18%, a special rate of 40% for a short list of goods, and a few rates for particular goods such as 3% on gold, 0.25% on rough diamonds and 1.5% on the items in one schedule. Many items are nil rated. Enter an amount and choose whether it is a taxable value to add GST to or an invoice total that already includes it. Pick a rate pill or type any rate, and say whether the supply is inside one state or between two. The calculator shows the GST, the taxable value, the total, the CGST and SGST halves for a sale within a state or the IGST for a sale across states, and the same amount at every listed rate. The arithmetic is done in the page, so the figures you type stay with you.
How to use the GST Calculator
- Enter the amount from the quote, bill or invoice.
- Choose whether that amount is before GST or already includes it.
- Tap a rate pill or type the GST rate of the item. Tip: Use 0 for an item that is nil rated or exempt.
- Choose a supply within one state or between states.
- Read the GST, the CGST and SGST or IGST, and the total.
Worked example
A seller in one state bills a buyer in the same state for goods with a taxable value of 10,000 at the standard 18% rate. All figures are INR.
| Input | Value |
|---|---|
| Amount | INR 10,000.00 before GST |
| GST rate | 18% |
| Supply | Within one state |
GST = 10,000 x 18% = 1,800 Invoice total = 10,000 + 1,800 = 11,800 CGST = 1,800 / 2 = 900 at 9%, and SGST = 900 at 9% Check: 11,800 / 1.18 = 10,000, so taking the GST back out gives the same split
- GST
- INR 1,800.00
- Total with GST
- INR 11,800.00
- CGST
- INR 900.00
- SGST
- INR 900.00
For a buyer in another state the same sale carries IGST of 1,800 at 18% in place of the two halves, and the invoice total stays 11,800.
How GST is added, removed and split
Adding: GST = taxable value x rate / 100, total = taxable value + GST
Removing: taxable value = total / (1 + rate / 100), GST = total - taxable value
Within one state: CGST = GST / 2, with any odd paisa, and SGST = GST - CGST
Between states: IGST = GST
When the amount is a taxable value, the GST is the value times the rate, rounded to the paisa, and the total is the two added together. When the amount is a total that already holds GST, the taxable value is the total divided by one plus the rate, rounded to the paisa, and the GST is whatever is left. Working it that way round means the taxable value plus the GST always equals the total typed, to the paisa.
India splits the tax on a supply inside one state between the two governments. The central tax, CGST, and the state tax, SGST, are each charged at half the rate, so 18% becomes 9% and 9%. The calculator splits the GST it worked out into two halves rather than rounding each half separately, so the halves never add up to more or less than the GST. On a supply from one state to another there is a single integrated tax, IGST, at the full rate, and the buyer's total does not change.
The rate pills follow the structure the GST Council recommended at its 56th meeting and the rate notification of September 2025: 5% and 18% for most goods and services, 40% for a short list, and the particular rates of 3%, 0.25% and 1.5% for the goods in their own schedules. A pill for 0% covers nil rated and exempt items. Any other rate can be typed with up to three decimals.
The table under the result runs the same amount through every listed rate, which helps when an item's rate is in doubt or when comparing an old quote with a new one. The calculator does not decide which rate an item carries; that comes from the classification of the goods or service in the notifications.
Not covered: input tax credit, the reverse charge, the composition scheme and the compensation cess.
Frequently asked questions
How do I add 18% GST to a price?
Multiply the taxable value by 18% and add the result. On 10,000 the GST is 1,800 and the invoice total is 11,800. For a sale inside one state that GST is split into CGST of 900 at 9% and SGST of 900 at 9%. For a sale to a buyer in another state it is a single IGST of 1,800 at 18%.
How do I take GST out of an amount that includes it?
Divide the total by one plus the rate, then subtract. An invoice total of 11,800 at 18% gives a taxable value of 11,800 / 1.18 = 10,000 and GST of 1,800. Taking 18% of 11,800 would give 2,124, which is wrong, because the GST was charged on 10,000 and not on the total that already holds it.
What are the GST rates after September 2025?
The GST Council's 56th meeting moved most goods and services to two rates, 5% and 18%, with a special rate of 40% for a few goods, from September 2025. The rate notification of that month also keeps 3% for goods such as gold, 0.25% for goods such as rough diamonds and 1.5% for a further schedule. Some items, such as UHT milk and paneer, are nil rated.
When is it CGST and SGST, and when is it IGST?
A supply where the seller and the place of supply are in the same state carries CGST for the central government and SGST for the state, each at half the rate. A supply from one state to another carries IGST at the full rate. The total tax on the invoice is the same either way; only the government that collects it changes.
Why can CGST and SGST differ by one paisa?
The calculator works out the whole GST, rounded to the paisa, and then splits it into two halves. When the GST ends in an odd paisa it cannot be halved exactly, so the central half takes the extra paisa and the two halves still add up to the GST shown. A billing system that rounds each half on its own can differ by a paisa.