About Contractor Calc
Contractor Calc is a free hub of construction calculators and templates built specifically for Australian contractors. We exist because the spreadsheets most builders use are out of date, and the SaaS tools want a credit card before they show you the maths.
Built for AU
Every calculator is tuned to AU practice — GST, retention conventions, common contract structures.
Reviewed by contractors
Working builders and quantity surveyors review the maths before each release.
Free, no signup
No accounts, no upsells, no email walls. Use it on site, share the link.
Our accuracy approach
All calculators use standard formulas, openly documented in the Resources section. We don't make commercial claims about the right number — only the maths from your inputs.
Disclaimer
Contractor Calc calculators are general tools and do not replace legal, accounting, or contract advice. Always confirm requirements for your state, contract type, and project with a qualified adviser.