Guide
About the GST Calculator
What is GST?
Goods and Services Tax (GST) is the unified indirect tax in India that replaced VAT, service tax and excise duty in 2017. GST is levied at four primary slabs — 5%, 12%, 18% and 28% — depending on the category of goods or services, with 0% on essentials and special rates of 0.25%/3% on a few items. For intra-state sales, GST is split equally into CGST (Central GST) and SGST (State GST). For inter-state sales it is collected as IGST.
How GST is calculated
There are two common ways to calculate GST. To add GST: GST = base × rate / 100, and total = base + GST. To extract GST from an inclusive amount: base = total / (1 + rate/100), and GST = total − base. Our GST calculator India handles both modes — useful for invoicing (exclusive) and for back-calculating from MRP (inclusive).
Example
If a service costs ₹10,000 (excluding GST) at 18%, the GST amount is ₹1,800 — split as ₹900 CGST and ₹900 SGST for an intra-state sale, or ₹1,800 IGST for inter-state. The customer pays ₹11,800 in total. Conversely, if an MRP is ₹1,180 inclusive of 18% GST, the actual taxable base is ₹1,000 and the GST component is ₹180. In 2026, GST registration is mandatory for businesses with turnover above ₹40 lakh (₹20 lakh for services).
Common GST rates in India
0% — essentials like fresh milk, fruits, vegetables, salt; 5% — packaged food, footwear under ₹1,000, transport services; 12% — processed food, mobile phones, business-class flights; 18% — most services, restaurants, telecom, software, financial services; 28% — luxury items, cars, tobacco, aerated drinks. Always check the latest CBIC notifications, as rates are revised by the GST Council periodically.