GST Calculator.

Adding and removing GST are two opposite operations, and choosing the right one depends on whether your starting amount already includes tax. Use add mode when your price is the net or taxable value before tax, for example a listed price of 1,000 rupees, and you want to know how much GST to add and what the customer finally pays. In that case 18 percent GST adds 180 rupees, giving a gross of 1,180 rupees. Use remove mode when your amount already includes GST, for example an all-inclusive price of 1,180 rupees, and you need to work backwards to find the taxable value and the tax hidden inside it, which here would be a net of 1,000 rupees and GST of 180 rupees. The maths differs in each direction: adding multiplies the net by the rate, while removing divides the gross by one plus the rate to recover the net. Getting the direction right matters for your invoice and your books, because a removed figure and an added figure on the same base are not the same number.

For a supply made within your own state, the total GST is split equally into two components, Central GST and State GST, each carrying half the total rate. So an 18 percent GST becomes 9 percent CGST plus 9 percent SGST, a 12 percent GST becomes 6 percent plus 6 percent, and so on. On the rupee amount the split is simply the total GST divided in two: if the total GST is 180 rupees, you show 90 rupees CGST and 90 rupees SGST. Both halves are always equal, and your tax invoice must show them as separate lines rather than a single combined GST figure, which is a compliance requirement. The calculator does this split automatically the moment you calculate, so you can copy the CGST and SGST figures straight onto your invoice. The two halves go to different governments, the central and the state, but for your billing they are simply two equal lines that together make up the GST you collect.

You use IGST, Integrated GST, when the supply is inter-state, meaning the place of supply is in a different state from where you are registered, and you use CGST plus SGST when the supply is intra-state, within the same state. IGST is a single line charged at the full rate, so on an 18 percent supply you show one IGST line of 18 percent rather than two halves. The total tax amount is the same either way, only the way it is presented and where it goes differs: intra-state tax is shared between the central and state governments as CGST and SGST, while inter-state tax goes as a single IGST that is later apportioned. The calculator shows the CGST and SGST split for the within-state case and notes the equivalent single IGST figure underneath, so whichever applies to your sale, you can read the right number. The key is the place of supply: if your customer is in another state, charge IGST; if in your state, charge CGST and SGST.

India has several GST slabs, and the common ones for small businesses are 5, 12, 18 and 28 percent, with some items at 0 percent and a few special rates. The slab depends on the specific goods or services you supply, classified under HSN codes for goods and SAC codes for services. As a rough guide, many essential and basic items sit at 5 percent, a range of processed goods and some services at 12 percent, the large default category of standard goods and most services at 18 percent, and luxury or so-called sin goods at 28 percent. However, the exact rate for your product is a matter of the official GST rate notifications, which are updated from time to time, so you should confirm your slab against the current notifications or with your accountant rather than guessing. This calculator does not decide the rate for you; it applies whichever slab you select, so the responsibility for choosing the correct slab remains with you. Once you know your rate, select it here and the tool handles the tax, split and totals.

Yes, this is a quick and useful way to verify that a supplier has applied GST correctly on an invoice you receive. If the invoice shows a taxable value and a GST amount, use add mode with the taxable value and the stated slab and check that the GST and gross match what the supplier printed. If you only have the all-inclusive total, use remove mode with that gross to confirm the taxable value and GST implied by the slab. This helps you catch common errors, such as the wrong slab being applied, the CGST and SGST not being split equally, or a within-state supply being charged as IGST or vice versa. Because the input tax credit you can claim depends on the invoice being correct, a quick check protects you from claiming the wrong amount or having credit disallowed later. For structural validation of the supplier GSTIN itself, our GSTIN validator complements this by confirming the tax number is well-formed before you rely on the invoice.

No, nothing you enter is stored or transmitted anywhere. The entire calculation, adding or removing GST, splitting it into CGST and SGST, and totalling the gross, happens inside your own browser using JavaScript on the page, so your amounts never reach our servers or any third party. There is no account, no login and no saved history, which means you can safely check real invoice values, prices and margins without any privacy worry, and the results appear instantly because nothing travels over the network. The trade-off is that the tool does not remember anything between calculations or visits, so if you want to keep a particular figure, copy it onto your invoice or note it down before you change the inputs. This local-only approach also means the calculator keeps working after the page has loaded even if your connection drops, since all the maths runs on your device rather than on a remote server, making it both private and dependable for everyday billing checks.

GST amounts on invoices are expressed in rupees and paise, so the calculator shows two decimal places to match how tax is actually recorded and to keep your figures accurate. When you remove GST from a tax-inclusive price, the net and the tax often do not come out to round rupees, for example removing 18 percent from 1,180 gives a clean 1,000 and 180, but removing it from 1,500 gives a net of about 1,271.19 and GST of about 228.81. Keeping the paise ensures the net, the CGST and SGST halves, and the gross all add up correctly, which matters because rounding too early can leave your invoice totals off by a paisa or two and cause small reconciliation mismatches. The amounts are also formatted in the Indian style, with commas placed for thousands, lakhs and crores, so larger values are easy to read. When you transfer the figures to your invoice, keep the two decimals as shown so the line items and the total reconcile exactly.