GST Calculator — India.

GST (Goods and Services Tax) is India's unified indirect tax, introduced on 1 July 2017 in place of VAT, service tax and excise duty. Since the GST 2.0 reform of 22 September 2025 there are two main slabs, 5% and 18%, and a 40% rate for luxury and sin goods. Shoppers use a GST calculator to check the tax on a bill, and businesses use it to price goods and raise correct invoices.

The formula. To add GST: GST amount = Base × rate ÷ 100 and Final = Base × (1 + rate ÷ 100). To remove GST from a tax-inclusive price: Base = Final ÷ (1 + rate ÷ 100), then GST = Final − Base. Here Base is the pre-tax price, rate is the GST percentage and Final is the price including GST.

Worked example. On a ₹1,000 item at 18% GST, the GST is 1,000 × 18 ÷ 100 = ₹180, so the final price is ₹1,180. For an intra-state sale that ₹180 splits into ₹90 CGST and ₹90 SGST. In reverse, a ₹1,180 inclusive price gives a base of 1,180 ÷ 1.18 = ₹1,000 and ₹180 of GST.

For intra-state transactions, GST is split equally into CGST (Central GST) and SGST (State GST). For inter-state transactions, IGST = full GST rate is applied.

Until 22 September 2025, India had four main slabs. GST 2.0 folded almost everything from the old 12% slab into 5%, and most of the old 28% slab into 18%. That cut the tax on everyday items such as packaged food, dairy and personal care, and on appliances such as air conditioners and televisions. Individual health and life insurance premiums became exempt.

A new 40% rate now covers luxury and "sin" goods: pan masala, tobacco, aerated and caffeinated drinks, large cars, motorcycles above 350 cc, yachts and private aircraft, as well as betting, casinos and online money gaming. Tobacco kept its old 28% rate plus compensation cess until 1 February 2026, when the cess ended and it moved to 40%.

A few special rates survive outside the main slabs. Gold and silver carry 3% and rough diamonds 0.25%. Enter those in the Custom % box. The rate on any single item depends on its HSN or SAC code, so check the official CBIC rate schedule or your invoice before you file.

Where it's used. GST appears on almost every Indian invoice: retail bills, restaurant receipts, phone and internet plans, online orders and professional services. Businesses rely on it to issue compliant invoices and claim input-tax credit, while shoppers use it to verify a bill or recover the pre-tax price from an inclusive amount.