GST Invoice Calculator
Split an invoice into taxable value and CGST, SGST or IGST line by line.
About the GST Invoice Calculator
On a sale within a state, GST is split equally into Central GST and State GST; on an inter-state sale it's charged as Integrated GST. Since 22 September 2025 most goods and services are at 5% or 18%, with 40% for sin and luxury goods. A tax invoice must show the GSTIN, HSN/SAC code, taxable value and tax for each item.
The formula
GST = Σ (qty × rate × GST%); CGST = SGST = GST ÷ 2
Worked example
Example: Invoice total = ₹52,450.00
- Inputs: Line items (description, qty, rate ₹, GST %): Consulting 1 40000 18; Travel 1 5000 5; Supply: Same state (CGST + SGST).
- Formula: GST = Σ (qty × rate × GST%); CGST = SGST = GST ÷ 2
- Result: Invoice total = ₹52,450.00
Questions people ask
When is IGST charged?
When the supplier's state and the place of supply differ, and on imports.
Do I round each line?
Tax is usually computed per line and rounded to the paisa.