Transparent formulas
Every tool explains the math and assumptions behind the estimate.
Measure twice. Calculate once.Construction math,
Construction math,
made practical.
Fast, transparent calculators for material quantities, roof geometry, floor area, stairs, and more—built for real project planning.
8 focused tools2 unit systems0 sign-ups
Most used tools
View all eight tools →Start with a solid estimate
Roofing
Roof Pitch Calculator
Convert any rise and run into X:12 pitch, angle, slope, and multiplier.
Open calculator →RoofingRafter Length Calculator
Estimate common-rafter geometry from horizontal run, roof pitch, and overhang.
Open calculator →MaterialsConcrete Calculator
Estimate concrete volume for rectangular slabs and footings, with waste and bag counts.
Open calculator →LayoutStair Calculator
Plan riser count, actual riser height, total run, stringer length, and angle.
Open calculator →Built for clarityNumbers you can follow,
Numbers you can follow,
not just answers.
Clean unit handling
Imperial and metric inputs stay separate, with useful converted results.
Practical guardrails
Inline checks catch impossible values, while limitations remain visible.
Quick answers
Plan with fewer surprises
These calculators provide planning estimates. Product yield, site conditions, workmanship, and local requirements can change actual needs.
Are these calculators free?
Yes. Every calculator works without an account or subscription.
Can I use metric measurements?
Yes. Relevant tools have clear imperial and metric modes.
Are results suitable for ordering materials?
Use them as a careful starting estimate, then confirm quantities with drawings, site measurements, suppliers, and qualified professionals.