GST Calculator India (Add or Remove GST)

How it works

To add GST, multiply the taxable value by the rate. To remove GST from an inclusive price, divide by (1 + rate) to get the taxable value first; simply subtracting the rate from the total gives the wrong answer.

For a sale within the same state, the tax is split equally into CGST and SGST (or UTGST). For a sale to another state, the full amount is IGST. Rates depend on the goods or service's HSN/SAC code; confirm the current rate on the official GST portal before invoicing.

Add GST:    GST = value × rate;  total = value + GST
Remove GST: value = total / (1 + rate);  GST = total − value
Intra-state: CGST = SGST = GST / 2

Worked example

A ₹10,000 service at 18% GST carries ₹1,800 of tax (₹900 CGST + ₹900 SGST within the state), for an invoice total of ₹11,800. Going the other way, an ₹11,800 GST-inclusive price contains ₹10,000 of taxable value.