I built free Australian tax calculators and published them on GitHub Pages

Talha — Mon, 09 Nov 2026 04:00:05 +0000

I've been building Instant Receipts — a receipt scanning and BAS prep app for Australian sole traders — and as part of that I built a set of free calculators that live on the main site.

Recently I extracted them into a standalone static site on GitHub Pages so they work without any framework, server or build step.

What's included

Six tools, all pure HTML/CSS/JS:

GST Calculator — add 10% GST to a price, or remove it using the 1/11th rule
BAS Calculator — work out G1, 1A and 1B for your Business Activity Statement
Sole Trader Tax Calculator — income tax, Medicare levy, HELP repayment and take-home pay
Mileage Calculator — ATO cents per km deduction (91¢/km for 2026-27)
Work From Home Calculator — ATO 70¢/hour fixed rate deduction
Invoice Generator — tax invoice with ABN, GST per line, download as PDF

Why pure HTML/JS

No npm install. No build step. No framework. Just open the file and it works.

The calculators run entirely in the browser — nothing is sent to a server, nothing is stored. For a tool that asks people to enter their income and expenses, that felt like the right call.

The GitHub Pages version is at instant-receipts-pty-ltd.github.io/australian-calculators if you want to see the source.

Australian tax is surprisingly specific

The GST 1/11th rule, BAS labels, the Small Business Income Tax Offset, ATO cents per km rates — none of this exists in any international calculator library. Had to build it all from scratch with the ATO's own documentation.

Happy to answer questions about the Australian tax side or the vanilla JS approach.

DEV Community: Talha

I built free Australian tax calculators and published them on GitHub Pages

What's included

Why pure HTML/JS

Australian tax is surprisingly specific