GST Calculator India

A GST calculator is a simple online tool that helps you add Goods and Services Tax to a base amount, or extract the GST component from a tax-inclusive price. It supports all standard Indian GST slabs (0%, 5%, 12%, 18%, 28%) and automatically splits the tax into CGST and SGST for intra-state transactions or shows the full amount as IGST for inter-state ones.

Whether you are a freelancer raising an invoice, a small business filing GSTR-1, a buyer cross-checking a vendor bill, or simply trying to back-calculate the price of a product before tax, this calculator gives you the breakdown in one click.

The standard formula to add GST is straightforward: GST Amount = (Base Price × GST Rate) / 100, and Total Price = Base Price + GST Amount. For example, on a ₹1,000 product at 18% GST, the GST is ₹180 and the customer pays ₹1,180 in total. The seller deposits the ₹180 with the government, after adjusting for any Input Tax Credit available.

To work backwards from a tax-inclusive price - say a customer-facing MRP of ₹1,180 at 18% GST - you divide by 1.18 to get the base price of ₹1,000. This reverse calculation is what most B2C buyers need when they want to know how much of the final price is going to the government.

When a transaction happens within a single state, the GST collected is split equally into CGST (Central) and SGST (State). On a ₹1,000 sale at 18% GST inside Maharashtra, the seller charges ₹90 CGST and ₹90 SGST. When the same ₹1,000 sale crosses state borders (say Maharashtra to Karnataka), the seller charges ₹180 IGST, which the centre later shares with the destination state.

The destination of the supply, not the location of the supplier, decides which tax applies. Software firms and e-commerce sellers must track place-of-supply rules carefully to avoid incorrect GST reporting and penalties.

0% slab: Fresh fruits and vegetables, milk, eggs, unbranded atta and pulses, books, newspapers, salt. 5% slab: Edible oils, branded packaged food, footwear under ₹1,000, train and economy-class air tickets, restaurants without AC. 12% slab: Processed foods, computer keyboards, mobile phones (since April 2020), business-class air tickets. 18% slab: Most services including telecom, banking, IT, AC restaurants, electronics, cosmetics. 28% slab: Luxury cars, tobacco products, aerated drinks, gambling, pan masala - often with additional cess.

Most services in India are taxed at 18% GST. The major exceptions are: passenger transport by rail or road (5%), residential construction services (12% with ITC or 5% without ITC for affordable housing), restaurants (5% without ITC, or 18% in starred hotels), and luxury/entertainment services (28%). Healthcare provided by clinical establishments, services by educational institutions up to higher secondary level, and basic agricultural services are exempt from GST entirely.

Service exporters under SEZ or Letter of Undertaking (LUT) can supply services to overseas clients at 0% GST while still claiming Input Tax Credit on inputs - making service exports particularly tax-efficient for Indian IT and consulting firms.

Use the reverse GST mode (Remove GST) when the amount you have already includes GST. Common scenarios: (1) Verifying a customer-facing invoice where MRP is GST-inclusive; (2) Splitting a restaurant bill where the printed total includes GST; (3) Computing the tax exclusive price for accounting or comparison; (4) Working out the ITC claim available on a tax-inclusive purchase voucher.

For a tax-inclusive amount of ₹1,18,000 at 18% GST, the base price is ₹1,00,000 and the GST is exactly ₹18,000. The reverse calculator does this division automatically.