GST Calculator
Free GST calculator online. Add or remove GST or VAT.
Add or remove GST and VAT
Use this free GST calculator online to add GST to a price or take GST out of a price that already includes tax. Enter the amount and the tax percent.
Works the same way for VAT in many countries. Confirm the rate that applies to your invoice.
For a simple percent of a number, the Percentage Calculator is quicker.
GST calculator FAQ
Fill in the fields above. The result updates as you type. Empty fields stay blank until you enter a valid number or text.
Yes. Every SmartToolX calculator and converter is free. There is no paywalled result.
No. Inputs stay in your browser unless a tool needs a public API, such as live currency rates or QR image rendering.
We use the same published formulas you would expect from a standard gst calculator. Always double-check medical, legal, or large money decisions.