Construction calculators that show their work
Every result comes with its formula, steps and assumptions — so you can check the math on the jobsite. Metric and imperial, free, no signup.
Browse all calculatorsMost used
- Concrete CalculatorSlabs, footings, walls, columns and steps in cubic yards, meters and 80 lb bags — waste and cost included.
- Stair CalculatorRisers, treads, stringer length and stair angle from total rise — with IRC code checks built in.
- Roofing CalculatorRoof area from footprint and pitch in squares, bundles and felt rolls — gable, hip and shed roofs.
- Drywall, Paint, Flooring & MoreDrywall sheets, paint gallons, flooring, stud counts and gravel tonnage in one estimator collection.
- Square Footage CalculatorRectangle, triangle and circle areas in square feet, yards and meters — repeat quantities and cost included.
- Cubic Yard CalculatorConvert length, width and depth into cubic yards, feet and meters with allowance and material cost.
- Deck CalculatorDecking boards, courses, joists and screws from deck size, board dimensions, spacing and waste.
- Fence CalculatorPosts, sections, rails, pickets and concrete with gate openings, spacing and waste included.
Popular guides
- How to Calculate Concrete — The L × W × T method, converting to cubic yards, waste factors, and when to order ready-mix vs bagged mix.
- How to Calculate Stairs — Rise and run, counting risers and treads, the comfort rule, and cutting a stringer from your numbers.
Why contractors trust these numbers
Each calculator is built from a written formula specification with automated reference tests — over a hundred verified cases covering boundary values and imperial/metric parity for the same physical scenario. Results snap to real tape-measure fractions (1/16", 1/32", 1/64") instead of floating-point dust.
Nothing here hides behind an app install or signup wall. Use it, copy the breakdown, get back to work.