What is ContractorMaths?
ContractorMaths is a free library of 200+ construction calculators covering every calculation a contractor, builder or tradie needs on the job. From concrete volumes and brick counts to labour costs, markup and project estimating — every tool is free, instant and requires no sign-up.
Who is it for?
Every construction professional: contractors and subcontractors pricing work, builders estimating materials, tradies calculating labour rates, project managers estimating costs, quantity surveyors checking takeoffs, and DIYers planning home improvements.
Metric and Imperial
ContractorMaths is designed for global use. Most calculators include a metric/imperial toggle — switch between metres, centimetres, kilograms and litres or feet, inches, pounds and gallons instantly. Whether you're in Australia, the US, UK or Canada, the tools work for you.
Why Free?
Construction professionals deserve accurate tools without paywalls or forced sign-ups. Every calculator on ContractorMaths is completely free — no credit card, no account, no limit on use.
Accuracy
Every calculator uses industry-standard formulas verified against Australian Standards, NCC requirements and international construction practice. Results are estimates for planning and quoting. Always verify structural calculations with a qualified engineer.