Pick intra-state to split GST equally into CGST and SGST, or inter-state to see IGST. The calculator uses the simplified GST 2.0 rate structure of 5%, 18% and 40%, along with the special 3% and 0.25% rates.
GST calculation formulas
GST = Value × Rate ÷ 100 | Base = Inclusive amount × 100 ÷ (100 + Rate)
- Exclusive
- Final price = Value + GST
- Inclusive
- GST = Inclusive amount − Base
- Intra-state
- CGST = SGST = GST ÷ 2
- Inter-state
- IGST = full GST
When the supplier and the place of supply are in the same state, the tax is shared equally between the Centre (CGST) and the State (SGST or UTGST). For supplies across states, and for exports and SEZ supplies, IGST applies.
Since 22 September 2025, most goods and services fall into the 5% merit rate or the 18% standard rate, with 40% reserved for sin and luxury goods. Gold and silver attract 3% and rough diamonds 0.25%.
Do you need GST registration?
Registration is mandatory once your aggregate turnover crosses ₹40 lakh for goods (₹20 lakh in special category states) or ₹20 lakh for services (₹10 lakh in special category states). Inter-state suppliers of goods and most e-commerce sellers must register regardless of turnover.
Registering voluntarily can also help, since it lets you claim input tax credit and work with larger business customers who prefer GST-compliant vendors.