GST calculator

Multiply the price by the GST rate and divide by 100 to get the GST amount, then add it to the price. For example, ₹1,000 at 18% has ₹180 GST, so the total is ₹1,180. Choose Add GST in the calculator above and it shows the GST amount, the split and the total for you.

Divide the inclusive price by one plus the rate. For ₹1,180 at 18%, 1,180 ÷ 1.18 = ₹1,000 before GST, so the GST inside it is ₹180. Don't simply subtract 18%, which gives the wrong answer. Choose Remove GST above and the calculator does the division for you.

They are parts of the same tax. CGST goes to the centre and SGST to the state when the sale is within one state, each at half the rate. IGST is charged at the full rate when the supplier and the place of supply are in different states. The customer pays the same total either way.

Charge IGST when the place of supply is in a different state from your registration, for example a Pune business selling to a customer in Bengaluru. Charge CGST plus SGST when the place of supply is in your own state. For services, the place of supply rules decide which state counts.

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. The old 12% and 28% rates still apply to a few items, and some, such as gold at 3%, have special rates. Always confirm your item's rate from its HSN or SAC code.

Look up your product's HSN code, or your service's SAC code, on the CBIC GST rate finder or in the official rate notifications. The rate depends on that code, not on your trade. If an item could fall under two codes, ask your CA, because the wrong rate on an invoice causes trouble later.

UTGST is union territory GST. It replaces SGST for supplies within union territories that don't have their own legislature, such as Chandigarh, Ladakh or Lakshadweep. It works the same way: half the rate is CGST and half is UTGST. Delhi and Puducherry use SGST because they have legislatures.

Yes, if the discount is shown on the invoice at the time of sale. GST is calculated on the price after that discount. Discounts given later, such as a year-end scheme, follow separate rules and usually need a credit note, so check those with your accountant before adjusting tax.

Tax is worked out to the paisa. This calculator rounds half up to the nearest paisa, and when CGST and SGST don't split evenly, the extra paisa goes to SGST. Many invoices then round the grand total to the nearest rupee with a separate round-off line, which is accepted practice.

Yes. Only a GST-registered business can charge GST and show a GSTIN on its invoice. Registration is required above the turnover threshold, generally ₹40 lakh for goods and ₹20 lakh for services, lower in some states, and in certain cases such as inter-state sales or selling through some marketplaces.

No. A business under the composition scheme pays tax at a fixed rate on its turnover and cannot collect GST from customers or claim input tax credit. It issues a bill of supply instead of a tax invoice, and must mention that it is a composition taxable person on that bill.

Input tax credit is the GST you paid on business purchases, which you can subtract from the GST you collect on sales. If you collected ₹18,000 and paid ₹10,000 on eligible inputs, you pay ₹8,000. Credit needs a valid invoice, the supplier's filing in GSTR-1 and the goods or services received.

Yes. It is free, works in any browser on a phone or laptop, and doesn't need a login or an email address. Nothing you type is stored. It is one of several free business tools from Marketiism, alongside the invoice generator, the GST late fee calculator and the EMI calculator.

Yes. Open the free GST invoice generator, enter the same item, rate and customer details, and it builds a printable tax invoice with the CGST and SGST or IGST split and your GSTIN. If you invoice every day, Marketiism creates numbered GST invoices automatically when customers pay.

Use them as a quick check. The calculator follows the standard formulas and rounding, but your returns depend on your invoices, credit notes and the correct rate for each item. For filing GSTR-1 and GSTR-3B, go by your books and confirm anything unusual with your CA.