Indian GST Calculator
Goods and Services Tax in India runs on five slabs — 0%, 5%, 12%, 18%, and 28%. This calculator handles both directions (add GST to a taxable value, or extract GST from an inclusive invoice total) and shows the CGST + SGST split for intra-state supply or the single-line IGST for inter-state. Useful for invoicing, reverse-charge calculations, and reconciling GSTR-3B.
The five GST slabs explained
- 0%
- Essential goods — fresh fruit, vegetables, milk, raw eggs, salt, sanitary napkins.
- 5%
- Basic necessities — sugar, tea, edible oil, packaged paneer, frozen vegetables, life-saving drugs.
- 12%
- Computers, processed foods, mobile phones, butter, ghee, processed cheese.
- 18%
- Most goods and services — soaps, toothpaste, capital goods, telecom services, IT services, hotels (₹1,001-₹7,500/night), restaurants (most), professional services.
- 28%
- Luxury and demerit goods — automobiles, ACs, refrigerators, tobacco products, aerated drinks. Some attract a compensation cess on top.
Intra-state vs inter-state supply
If the buyer and seller are in the same state (intra-state), GST is split equally between Central GST (CGST) and State GST (SGST). An 18% GST line splits into 9% CGST + 9% SGST.
If the supply crosses state lines (inter-state), the whole 18% becomes Integrated GST (IGST), a single line on the invoice. The central government collects IGST and apportions it to the destination state under the GST settlement formula.
Worked example
A Mumbai-based design agency invoices a client. Taxable value of services: ₹50,000. GST slab for design services: 18%.
- If the client is also in Maharashtra: total GST ₹9,000 = ₹4,500 CGST + ₹4,500 SGST. Invoice total: ₹59,000.
- If the client is in Karnataka: total GST ₹9,000 = ₹9,000 IGST (single line). Invoice total: ₹59,000.
The invoice total is the same; only the line-item split changes.
Frequently asked questions
- Is this for the regular or composition scheme?
- Regular. Composition uses different effective rates on turnover and isn't computed this way.
- Does it handle the GST compensation cess?
- No — cess is item-specific and varies. This calculator handles the base GST only.
- Is this official?
- No, it's a maths tool. For binding GST treatment of specific transactions, consult a CA or refer to gst.gov.in.