GST calculator
Enter an amount, choose whether GST is extra or already included, and pick the rate. The taxable value, GST and total update instantly in your browser.
Result
- Taxable value
- ₹10,000.00
- GST @ 18%
- ₹1,800.00
- Total invoice value
- ₹11,800.00
GST rates and rules change. Please verify current rules with official government sources or your CA before filing.
How the two directions work
GST extra is the normal invoicing case: you know the price before tax, so GST = amount × rate ÷ 100 and the total is amount + GST. On a ₹10,000 sale at 18%, GST is ₹1,800 and the invoice total is ₹11,800.
GST included is the reverse — useful for MRP or counter prices. Taxable value = amount ÷ (1 + rate ÷ 100), and GST is whatever is left. On a ₹11,800 inclusive price at 18%, the taxable value is ₹10,000 and GST is ₹1,800.
Which rate applies?
GST rates depend on the HSN or SAC code of what you sell. Common slabs are 5%, 12%, 18% and 28%, with 0.25% and 3% used for specific goods such as stones and precious metals, and some items exempt. Rates and rules change — verify the current rate for your HSN/SAC with official government sources or your CA before you invoice.
Do this per line item, automatically
BillBook applies each item's own GST rate and discount, splits the tax into CGST/SGST or IGST from the place of supply, and gives you the invoice PDF — ₹299 once.
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