GST Calculator
Calculate GST instantly. Add GST to a base price or remove GST from an inclusive amount, at any standard rate, with the CGST and SGST split shown automatically.
How to calculate GST
To add GST to a base amount, multiply the amount by the GST rate and add it to the original price. For example, at 18% GST, a ₹1,000 product costs ₹1,000 + ₹180 = ₹1,180. To remove GST from a GST-inclusive price, divide the total by (1 + rate/100); the difference is the GST component.
For intra-state supplies, GST is split equally into CGST (Central GST) and SGST (State GST) — so 18% becomes 9% CGST + 9% SGST. For inter-state supplies, the same rate is charged as a single IGST (Integrated GST).
India's common GST slabs are 5%, 12%, 18% and 28%, with some goods at 0% (exempt) or special rates. Choosing the correct rate (HSN/SAC classification) is essential for compliant invoicing — EvoTax can help set this up.
Frequently Asked Questions
What are the GST rates in India?
The main GST slabs are 5%, 12%, 18% and 28%. Essential items are often exempt (0%) or at 5%, while luxury and sin goods attract 28% plus cess. The applicable rate depends on the HSN code for goods or SAC code for services.
What is the difference between CGST, SGST and IGST?
For sales within the same state, GST is split into CGST (to the centre) and SGST (to the state), each half the total rate. For inter-state sales, a single IGST is charged at the full rate. This calculator shows the CGST/SGST split for intra-state transactions.
How do I remove GST from an inclusive price?
Divide the GST-inclusive total by (1 + rate/100). For 18% GST, divide by 1.18 to get the base price; the remainder is the GST. Select "Remove GST" mode above to do this automatically.
Is GST calculated on the discounted price?
Yes. GST is charged on the transaction value after any discount shown on the invoice. Post-sale discounts have specific conditions. We can advise on correct invoicing for your business.
Do I need to register for GST?
Registration is mandatory above ₹40 lakh turnover for goods (₹20 lakh for services in most states), and for inter-state suppliers and e-commerce sellers. EvoTax handles GST registration end to end.
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