Calculate GST for intra-state (CGST + SGST) or interstate (IGST) transactions, in either GST-exclusive (add GST) or GST-inclusive (extract GST from a total) mode.
How to use the GST & Tax Calculator (HSN Lookup)
- Choose whether your amount is GST-exclusive or already includes GST.
- Enter the amount and applicable GST rate.
- Tick the box if it's an interstate transaction.
- Read the base amount, GST breakdown, and total invoice value.
Why use FreeToolsNets's GST & Tax Calculator (HSN Lookup)?
- 100% free, with no usage limits and no account required.
- Everything runs locally in your browser — nothing you type is uploaded or stored on a server.
- Works on desktop, tablet and mobile in any modern browser.
- No installation, no plugins, and no ads blocking the tool itself.
Frequently asked questions
What's the difference between CGST/SGST and IGST?
CGST and SGST apply to transactions within the same state and split the GST rate equally; IGST applies to interstate transactions and is collected entirely by the central government.
Where do I find the correct GST rate for my product?
Look up its HSN (goods) or SAC (services) code in the official GST rate schedule — common software/IT services are 18%.
Is this tool free to use?
Yes, completely free on FreeToolsNets, with no sign-up and no limits.
Is my data sent to a server?
No. Everything runs locally in your browser using JavaScript — nothing you enter is uploaded anywhere.
Does it work on mobile?
Yes, the widget is fully responsive and works on phones, tablets and desktops.