Construction calculators
Every calculator on one page. Each one shows the formula, the worked steps and its assumptions next to the answer — free, no signup, works offline after your first visit.
14 calculators
Measurements
- Feet and Inches CalculatorAdd, subtract, multiply and divide measurements in feet, inches and fractions — plus instant metric conversion.
- 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.
Materials
- Concrete CalculatorSlabs, footings, walls, columns and steps in cubic yards, meters and 80 lb bags — waste and cost included.
- Board Foot CalculatorLumber volume in board feet from thickness, width and length — price per bf and cut lists included.
- Rebar CalculatorRebar grid spacing, linear feet, stick count and weight for slabs — US #3–#18 and metric sizes.
- Brick CalculatorBricks, CMU blocks and mortar bags for any wall size, with openings, wythes and adjustable joints.
- 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.
- 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.
- Siding CalculatorSiding squares and panels from wall area, gables, doors, windows, course exposure and waste.
- Insulation CalculatorBags, rolls or bundles from project area and the manufacturer’s package coverage, plus waste and cost.
Layout & geometry
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.