GST Calculator
Add or remove GST, split it into CGST/SGST or IGST, and see the taxable value and total — in seconds.
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How GST is calculated
Goods and Services Tax (GST) is India's destination-based indirect tax on the supply of goods and services. The tax you charge depends on the GST rate (slab) for the item and on where the supply happens: within a state the tax splits into Central GST (CGST) and State GST (SGST), each half the slab; across states a single Integrated GST (IGST) applies at the full slab. This calculator works both ways — when your amount is GST-exclusive (add GST on top) and when it is GST-inclusive (extract the GST already inside the price).
Why it matters
Charging the wrong split (CGST/SGST vs IGST) or mixing up inclusive and exclusive amounts is one of the commonest invoicing errors — it distorts your tax liability and your customer's input tax credit. Getting the taxable value, the GST amount and the split right on every invoice keeps your returns clean.
Frequently asked questions
What is the difference between CGST, SGST and IGST?
For a supply within the same state, GST is split equally into CGST (to the Centre) and SGST (to the State). For a supply between two states, a single IGST at the full rate applies instead.
What does GST-inclusive vs GST-exclusive mean?
Exclusive means your amount is the taxable value and GST is added on top. Inclusive means the price already contains GST, so the tax is extracted by dividing by (1 + rate).
What are the GST slabs?
The common GST rates are 5%, 12%, 18% and 28%, with 0% for exempt items and 3% for bullion. The right slab depends on the specific good or service.
How is GST extracted from an inclusive price?
Taxable value = inclusive price ÷ (1 + rate). GST = inclusive price − taxable value. For example, ₹118 at 18% inclusive gives a taxable value of ₹100 and GST of ₹18.
This is an estimate to illustrate how GST is calculated — not tax advice. Confirm the correct rate and place of supply for your transaction with your CA.