GST Calculator – Add or Remove GST in One Step
10,000.00
Amount before GST
1,800.00
GST
11,800.00
Total with GST
Since 22 September 2025 most goods and services are taxed at 5% or 18%, with 40% for a short list of luxury and “sin” goods; 12% and 28% remain for invoices dated before that. Check the rate for your item against the official GST schedule.
About GST Calculator
Type an amount, pick a GST rate and choose whether the amount is before tax or already includes it. You get the tax, the pre-tax value and the final price at once, split into CGST and SGST for a sale within your state or IGST for a sale to another state.
Most GST mistakes come from removing tax the wrong way. If a price of ₹1,180 includes 18% GST, taking 18% off it gives ₹967.60 — but the real pre-tax value is ₹1,000, because the 18% was charged on ₹1,000, not on ₹1,180. The correct way is to divide by 1.18. The Remove GST mode does exactly that, so the figures match what a proper tax invoice would show.
The split between central and state tax depends only on where the goods or services go. A sale inside one state carries CGST and SGST, each half of the total rate — 9% + 9% for an 18% item. A sale to a buyer in another state carries the full rate as IGST. The total tax is the same either way; only the heads it is recorded under change.
Rates changed on 22 September 2025, when the GST Council merged most items into two main slabs of 5% and 18% and added a 40% rate for a short list of luxury and 'sin' goods. Gold stays at 3% and rough diamonds at 0.25%. The older 12% and 28% slabs are still here for checking bills issued before the change. Always confirm the rate for a specific item against the official schedule — this tool does the arithmetic, not the classification.
Worked examples, with real numbers
Adding GST: a freelancer quotes ₹50,000 for a service taxed at 18%. The GST is ₹9,000 and the invoice total is ₹59,000. Within the same state that ₹9,000 is shown as ₹4,500 CGST plus ₹4,500 SGST; for a client in another state the whole ₹9,000 appears as IGST.
Removing GST: a shop bill says ₹2,499 including 5% GST. Divide by 1.05 and the pre-tax price is ₹2,380, so the tax inside the bill is ₹119 — not the ₹124.95 you would get by taking 5% of ₹2,499. At 40%, a ₹10,000 inclusive price holds ₹2,857.14 of tax and ₹7,142.86 of value; subtracting 40% would wrongly claim ₹4,000.
Add GST or Remove GST: which mode to use
Use Add GST when you are the seller pricing something, because your starting point is the amount you want to earn before tax. Use Remove GST when you are holding a final price — a shop receipt, a supplier quote quoted all-inclusive, an MRP — and want the tax-free value underneath it. If a figure is described as 'inclusive of all taxes', 'MRP' or 'final price', it almost always belongs in Remove GST.
If you are reconciling a bill, enter its total in Remove GST and compare the tax shown against the invoice. A difference of a rupee or two is usually rounding on individual line items; a larger gap suggests the wrong rate was applied.
What this calculator does not decide
It does the arithmetic for a rate you choose; it does not tell you which rate applies to your goods or services. Classification — the HSN or SAC code and the slab it falls in — comes from the official GST rate schedule, and some items are exempt or taxed differently depending on how they are supplied. Check the schedule, or ask your accountant, for anything you will file a return on.
It also shows a single rate on a single amount. An invoice with several items at different rates should be calculated item by item and added up, because GST is charged per line, not on the grand total. Cess, reverse charge and input tax credit are outside what this page models.
Common mistakes
Subtracting the percentage instead of dividing is the most common error, and it grows with the rate: at 18% it overstates the tax by about 18% of the tax itself. Entering a GST-inclusive amount in Add GST double-charges the tax. And using the old 12% or 28% slabs on a bill dated after 22 September 2025 will not match what a supplier is now allowed to charge on most goods.
What you can use it for
- Work out the GST to add on a quotation or invoice before sending it.
- Find the pre-tax value hidden inside a GST-inclusive price on a bill.
- Split the tax into CGST and SGST, or IGST, for bookkeeping entries.
- Check that a supplier's invoice has charged the right amount of GST.
- Compare what an item costs at 5%, 18% or 40% before pricing it.
How it works, step by step
- 1
Choose Add GST or Remove GST
Add GST if your amount is before tax; Remove GST if it already includes tax.
- 2
Enter the amount
Indian-style commas like 1,25,000 are fine.
- 3
Pick the rate
Tap a common slab or type any rate, such as 12 or 0.25.
- 4
Choose the supply type
Within your state shows CGST + SGST; another state shows IGST.
Frequently asked questions
How do I remove GST from an inclusive price?
Divide the price by 1 plus the rate. For 18%, divide by 1.18: ₹1,180 ÷ 1.18 = ₹1,000, so the GST is ₹180. Subtracting 18% of ₹1,180 would wrongly give ₹212.40 of tax.
What is the difference between CGST, SGST and IGST?
For a sale within one state the tax is shared equally between the Centre (CGST) and the state (SGST). For a sale between states the whole tax is IGST. The total amount of tax is the same.
What are the GST rates now?
From 22 September 2025 the main slabs are 5% and 18%, with 40% for a small group of luxury and sin goods, 3% for gold and 0.25% for rough diamonds. Many essentials are exempt. Check the official GST rate schedule for a specific item.
Can I use a rate that isn't listed?
Yes. Type any rate between 0 and 100 into the rate box — decimals such as 0.25 work too.
Is anything I enter sent anywhere?
No. The calculation happens in your browser and nothing is uploaded or saved.