Free GST Calculator Online

Anyone running a small business, freelancing, raising an invoice, or just trying to understand whether the price tag in a shop already includes tax has needed a GST calculator at some point. Ours handles every common Indian-GST scenario in one place: add GST on top of a base price (the most common case for invoices and quotations), extract GST from a tax-inclusive price (working backwards from an MRP or shop price), and split the result into the correct CGST/SGST or IGST components depending on whether the transaction is intra-state or inter-state. Standard Indian GST slabs are one-click presets — 3% (gold and jewellery), 5% (essential items, transport, small restaurants), 12% (processed foods, business-class flights), 18% (most services and standard goods), and 28% (luxury items, automobiles) — and a custom field handles non-standard rates including the 0.25% rough-diamond rate or comparable VAT/sales-tax rates from other countries. Common workflows: a freelancer raising a ₹50,000 service invoice and needing to add 18% IGST for an out-of-state client, a shopkeeper figuring out the base price of an item priced at ₹1,180 inclusive of 18% GST so they can mark up correctly, an accountant cross-checking a vendor invoice where the line totals do not add up, a customer at a restaurant wondering whether the bill already includes GST or it is going to be added at the bottom, and a small e-commerce seller working out the GST portion of every order before filing GSTR-1. The arithmetic uses the standard Indian GST formulas: GST amount = base × rate / 100 for tax-exclusive prices, and base = inclusive / (1 + rate/100) for tax-inclusive prices. Use it for quick day-to-day calculations and reference, but for actual filing and official invoices, generate them through certified accounting software (Tally, Zoho Books, ClearTax, etc.) — the calculator does not produce GSTIN-compliant invoices. Pair this with our [Invoice Generator](/tools/invoice-generator) for printable invoices, the [Percentage Calculator](/tools/percentage-calculator) for non-GST tax maths, and the [EMI Calculator](/tools/emi-calculator) for loan-related planning.