GST Calculator

How to calculate GST in India

GST (Goods and Services Tax) is charged as a percentage of a product or service's price, and the arithmetic is refreshingly simple. To add GST, multiply the base amount by the rate and add it on: ₹10,000 at 18% gives ₹1,800 of GST and an ₹11,800 total. To remove GST from a price that already includes it, divide the total by 1 plus the rate — an ₹11,800 inclusive price at 18% works back to a ₹10,000 base and ₹1,800 of tax. Both directions matter in practice: shops quote GST-inclusive prices to customers but must report the tax separately, while quotations to businesses are usually GST-exclusive.

This calculator handles both, at any slab, and then does the part most people find fiddly — splitting the GST into its CGST, SGST or IGST components based on whether the sale is within your state or across state lines.

GST 2.0: the 2025 slab overhaul most calculators missed

On 22 September 2025, the biggest change since GST launched took effect. The 56th GST Council meeting collapsed the old five-slab system (0/5/12/18/28%) into a leaner structure: 0%, 5%, 18% and 40%. The 12% and 28% slabs were abolished — almost all 12% items dropped to 5%, and roughly 90% of 28% items fell to 18%, making everyday goods from shampoo to televisions noticeably cheaper. In their place, a single high 40% ratenow targets sin and luxury goods: tobacco, aerated drinks, high-capacity motorcycles, luxury cars and gambling. Compensation cess was scrapped except on tobacco products. If you see a GST calculator still offering 12% and 28% as standard slabs, it hasn't been updated — this one has.

CGST, SGST, IGST and UTGST — one tax, split by geography

GST looks like one number on your bill, but where that money goes depends on the transaction. For an intra-state sale (buyer and seller in the same state), the tax is divided equally: half is CGST for the central government and half is SGST for the state — so 18% is charged as 9% + 9%. For an inter-state sale or an import, the entire amount is charged as IGST, which the Centre collects and routes to the destination state. In the union territories, UTGST takes the place of SGST. Critically, you never pay more or less because of this split — the total GST is the same; only the accounting differs. The calculator shows the exact rupee split so your invoice lines up.

Which slab applies to what

0% covers essentials — fresh food, unbranded staples, life-saving medicines, notebooks, and now health and life insurance premiums. 5% is for daily necessities like packaged food, household and personal-care items, footwear and most medicines. 18% is the workhorse standard rate that applies to the majority of goods and nearly all services — from electronics and appliances to telecom, professional and financial services. 40% is reserved for a short list of sin and luxury products. Because classification hinges on the specific HSN or SAC code — and sometimes on price or packaging — always confirm a particular item on the official cbic-gst.gov.in portal before you invoice.

GST for freelancers and small businesses

If you supply goods or services, GST registration is generally required once turnover crosses the threshold (commonly ₹40 lakh for goods and ₹20 lakh for services, lower in some special-category states). Registered businesses charge GST on sales but claim back the GST paid on their purchases as input tax credit, so tax effectively applies only to the value they add. This tool computes the GST on any single amount; for the bigger picture of what you keep after tax, pair it with our income tax calculator and, if you freelance, the presumptive-taxation route under Section 44ADA.