GST Calculator
Add GST to a price or take it out of a total, split it into CGST and SGST or IGST, total a whole bill, and see your profit after GST.
Free, no sign-up. Everything runs in your browser.
- Price before GST
- ₹1,000.00
- CGST 9%
- ₹90.00
- SGST 9%
- ₹90.00
- Total GST
- ₹180.00
- Price with GST
- ₹1,180.00
GST = ₹1,000.00 x 18 / 100
Step by step
How to use GST Calculator
- 1
Choose the calculator
Add / remove GST for one amount, Invoice total for a bill with many items, or Profit margin.
- 2
Type the amount
Say whether the amount is before GST or already includes it.
- 3
Pick the rate and the buyer
Choose the GST rate, and whether the buyer is in your state (CGST + SGST) or another state (IGST).
- 4
Read or copy the result
The answer updates as you type. Press Copy to paste it into WhatsApp, a bill book or a sheet.
Overview
About GST Calculator
GST is added on the price before tax. At 18%, a ₹1,000 item costs ₹1,000 + ₹180 = ₹1,180. To take GST out of a price that already includes it, do not subtract 18%; divide instead: ₹1,180 x 100 / 118 = ₹1,000. This calculator does both, at any rate, and shows the working.
When the buyer is in your own state, the GST is split in half: CGST goes to the centre and SGST to the state, so 18% becomes 9% + 9%. When the buyer is in another state, the whole tax is IGST. Each half is worked out separately and rounded to the paisa, the way billing software does it.
Invoice total adds up a bill with up to 50 items at different rates, groups them by rate, and rounds the grand total to the nearest rupee with a round-off line and the amount in words. Profit margin shows what you really keep from a sale: the GST you collect is not your income, and the GST you paid on your stock comes back as input tax credit.
Everything runs in your browser. Nothing you type is sent anywhere.
When it helps
- A shopkeeper finding the price without GST from an MRP or a total that includes GST
- Checking the CGST, SGST or IGST on a supplier's bill before paying it
- Adding up a bill with items at 5% and 18% before writing it in the bill book
- Setting a selling price that leaves a 20% margin after GST
Specs
Supported files and limits
- Rates
- 0.25, 3, 5, 12, 18, 28 and 40%, or any rate from 0 to 100
- Tax split
- CGST + SGST for a buyer in your state, IGST for another state
- Rounding
- Each tax to the nearest paisa (half up); bill total to the nearest rupee
- Invoice
- Up to 50 items, prices before or including GST, total by rate, amount in words
- Largest amount
- ₹100 crore
- Where it runs
- In your browser. Nothing is uploaded.
GST on ₹1,000 at each rate
Adding GST: total = price x (100 + rate) / 100. Removing it: price = total x 100 / (100 + rate).
| Rate | GST on ₹1,000 | ₹1,000 + GST | ₹1,000 without GST |
|---|---|---|---|
| 3% | ₹30.00 | ₹1,030.00 | ₹970.87 |
| 5% | ₹50.00 | ₹1,050.00 | ₹952.38 |
| 12% | ₹120.00 | ₹1,120.00 | ₹892.86 |
| 18% | ₹180.00 | ₹1,180.00 | ₹847.46 |
| 28% | ₹280.00 | ₹1,280.00 | ₹781.25 |
| 40% | ₹400.00 | ₹1,400.00 | ₹714.29 |
Good to know
- It does not tell you which rate applies to your item. Check the HSN or SAC code on the CBIC website or with your accountant.
- It does not make a GST tax invoice. For that you need your GSTIN and billing software or a printed bill book.
- Compensation cess and TCS/TDS are not included.
- Profit margin assumes you claim input tax credit on your purchases. If you are under the composition scheme, enter your cost with GST and set the rate to 0.
Fix a problem
Troubleshooting
CGST + SGST is 1 paisa different from IGST
Each half is rounded on its own, as on real bills. The difference is normal and at most 1 paisa.
Taking 18% off my total gives a different answer
Subtracting 18% of the total is wrong, because the GST was 18% of the lower price. Use With GST (remove) here.
My bill software shows a slightly different total
Some software works out GST on each line instead of on each rate. Totals can differ by a few paise.
The margin box says it must be under 100%
A margin is profit divided by the selling price, so it can never reach 100%. For profit compared with cost, choose Markup.
FAQ
Frequently asked questions
How do I calculate 18% GST on ₹1,000?
18% of ₹1,000 is ₹180, so the total is ₹1,180. Within your state that is CGST ₹90 + SGST ₹90; for another state it is IGST ₹180.
How do I remove GST from a total?
Multiply the total by 100 and divide by 100 + the rate. For ₹1,180 at 18%: 1,180 x 100 / 118 = ₹1,000, so the GST was ₹180.
What is the price without GST if ₹500 includes 5% GST?
500 x 100 / 105 = ₹476.19. The GST in it is ₹23.81.
What is the difference between CGST, SGST and IGST?
For a sale inside one state, the GST is split equally into CGST (central) and SGST (state). For a sale to another state, the full GST is IGST.
What are the GST rates now?
Since 22 September 2025 most goods and services are taxed at 5% or 18%, with 40% on a few luxury and sin goods, plus special rates such as 3% on gold. The rate for your item depends on its HSN or SAC code.
What is the difference between margin and markup?
Both use profit = selling price - cost, before GST. Margin divides it by the selling price; markup divides it by the cost. Cost ₹800 and selling price ₹1,000 means ₹200 profit: 20% margin, 25% markup.
What price should I charge for a 20% margin?
Divide the cost by 0.8. For a cost of ₹800 that is ₹1,000 before GST, or ₹1,180 to the customer with 18% GST.
Is the GST I collect my profit?
No. You collect it from the customer and pay it to the government, after taking off the GST you paid on your purchases. That is why the profit here uses prices before GST.
Is my data saved or uploaded?
No. The sums happen in your browser and nothing is stored or sent.
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