GST calculator
How much GST is on this price, or inside it?
The price before tax when adding, the price on the bill when removing.
"Remove" works backwards from a tax-inclusive price — the ÷1.18 nobody gets right in their head.
Within a state the rate splits into CGST + SGST; across states it is one IGST. The total is identical either way.
₹1,800of GST at 18%
- Price before GST
- ₹10,000
- Price with GST
- ₹11,800
- CGST
- ₹900
- SGST
- ₹900
Figures carry paise inside the calculation and round to rupees on screen, because 18% of ₹1,199 genuinely is ₹215.82 and CGST + SGST has to add back up to it. The four slabs are the standard ones — 0%, 3% on gold and the cess on cars and tobacco are not here.
| Slab | GST | Price with GST |
|---|---|---|
| 5% | ₹500 | ₹10,500 |
| 12% | ₹1,200 | ₹11,200 |
| 18% | ₹1,800 | ₹11,800 |
| 28% | ₹2,800 | ₹12,800 |
Two different jobs wear the same word. Adding GST is easy arithmetic and nobody needs help with it. Pulling GST back out of a price that already contains it is the one people get wrong, because you cannot take 18% off a tax-inclusive bill — you have to divide by 1.18, and the answer is smaller than the number you expected. This does both directions, and it splits the tax the way an invoice has to: half to the centre and half to the state when buyer and seller are in the same state, one combined IGST line when they are not.
A worked example
A laptop invoice for ₹87,499, everything included, bought from a shop in your own state at the 18% slab. Set Amount to 87499, Rate to 18%, Direction to Remove GST and Supply to Same state. The page returns:
- ₹13,347 of GST
- ₹74,152 was the price before tax
- ₹87,499 is the price on the bill, unchanged — removing GST does not make the bill smaller, it tells you how it was built
- ₹6,674 CGST and ₹6,674 SGST, the two halves the invoice must print
- ₹74,152 Taxable value — what the laptop costs
- ₹13,347 GST at 18% — split ₹6,674 centre, ₹6,674 state
The tax is 18% of the smaller slice, not of the total — which is why it comes to 15.3% of what you actually handed over.
Change Supply to Other state and nothing in that split moves. The two ₹6,674 lines collapse into one IGST line of ₹13,347. Place of supply decides who the money reaches, never how much of it leaves you.
The mistake this exists to stop
Adding and removing are not two spellings of the same sum. Put the same ₹87,499 in at the same 18% and the two directions are ₹2,403 apart.
| Add GST | Remove GST | |
|---|---|---|
| What ₹87,499 means | The price before tax | The price on the bill |
| GST | ₹15,750 | ₹13,347 |
| Price before GST | ₹87,499 | ₹74,152 |
| Price with GST | ₹1,03,249 | ₹87,499 |
Both columns are correct — for different questions. Reading a quote as tax-exclusive when it was inclusive overstates the tax by ₹2,403 here.
So the direction is not a preference. It is a fact about the number you were given, and the only reliable tell is the paperwork: a quotation usually states a value and adds tax below it, a retail price tag and an MRP are inclusive, and a proper tax invoice shows both, with the taxable value and the CGST, SGST or IGST lines printed separately.
What this figure does not account for
Cess, and rates outside these four
The calculator offers the four rates 5, 12, 18 and 28 per cent. Nil-rated goods, the 3% on gold and 0.25% on rough diamonds, and the compensation cess that rides on top of the top slab for things like tobacco and large cars are all outside it. The GST Council revises both the slab structure and which items sit in which — it restructured them in September 2025 — so read the rate notification for the HSN or SAC code printed on your invoice as the authority, and treat the rate you pick here as the one you were charged, not as proof of the one that applies.
One line, not one invoice
This taxes a single amount at a single slab. A real bill mixes slabs — the phone at one rate, the case at another, freight at the rate of the goods it carries — and the invoice total is the sum of those lines, not this calculation run once on the grand total at a blended rate.
The taxable value is not always the sticker price
Under section 15 of the CGST Act the value of a supply pulls in packing, freight, commission and any other incidental charge the supplier bills, and excludes only discounts recorded on the invoice itself. Type the price and you get the tax on the price; the invoice may compute it on a larger value.
Who pays is a separate question
Under reverse charge, on notified supplies, the recipient pays the GST directly instead of the supplier collecting it — the amount is the same, the payer is not. A composition dealer under section 10 cannot charge you GST at all and must say so on the bill; the tax is inside their price, and you get no credit for it.
Income-tax TDS is not netted off here
If you are paying a contractor or a professional, tax deducted at source under the Income-tax Act is worked out on the value excluding GST when the GST is shown separately, and it comes off what you remit — not off what you owe. Two different taxes, two different bases, one invoice.
Where to go next
If the invoice you are reading is one you are being paid on, the TDS calculator is the other half of it — what the payer withholds before the money arrives. For the reverse-percentage arithmetic in general, a discount back to list price or a hike back to a base, the percentage calculator handles it without the tax vocabulary. And if the purchase is an under-construction property, GST is only one of the levies on it: the stamp duty calculator covers the state charge that sits alongside it and is not creditable against anything.
How do I remove 18% GST from a price?
Divide by 1.18, do not subtract 18%. A bill of ₹87,499 that already includes 18% GST breaks into ₹74,152 of value and ₹13,347 of tax. Subtracting 18% instead would give ₹71,749, which is wrong by more than two thousand rupees, because the 18% was charged on the smaller pre-tax figure, not on the total you are holding. Set Direction to "Remove GST" and the calculator does the division.
Is GST 18% or 9% CGST plus 9% SGST?
Both describe the same tax. Eighteen per cent is what you pay; within a state it is collected as two halves, 9% Central GST and 9% State GST, and the invoice must show them as separate lines. When the supplier and the place of supply are in different states there is no split — one Integrated GST line carries the whole 18%, and the centre later settles the state's share. Your total is identical either way, which is the point of the design.
Why don't CGST and SGST add up to the GST figure shown?
Because the tax is halved before it is rounded. On ₹87,499 inclusive of 18%, the GST is ₹13,347.31 and each half is ₹6,673.66 — on screen they read ₹6,674 and ₹6,674, a rupee more together than the ₹13,347 above them. The calculator carries paise all the way through and rounds only where it prints, which is why the halves are exact and the display is a rupee out. On a real invoice section 170 of the CGST Act settles it: the tax amount is rounded off to the nearest rupee.
Can I claim back the GST I paid on this?
Only if you are registered under GST and bought it for your business, in which case the tax is input tax credit rather than a cost, and the credit depends on the supplier actually filing the invoice. Section 17(5) of the CGST Act blocks the credit on a list of things anyway — most motor cars, food and beverages, club and health-club membership, and staff-welfare items. For an individual buying anything at all, GST is final: there is no refund route, so the tax-inclusive number is the number you paid.
Does MRP already include GST?
Yes. Maximum retail price is defined as the price inclusive of all taxes under the Legal Metrology (Packaged Commodities) Rules, so a shop that adds GST on top of the printed MRP is overcharging you. Use "Remove GST" on the MRP if you want to see the tax hiding inside it — but read the answer as information, not as money you can get back.
This page starts from typical figures. In Hundo the same calculator opens on your own — the loan, the deposit, the salary already on the ledger — and says where each number came from.