Construction formulas

A = π r², then C = A × price.

Half of π r² times length, then convert to cubic yards.

Compute π r² h, then convert cubic feet to cubic yards (÷ 27).

Sum n × (tread × rise / 2) × width, then convert to cubic yards.

Multiply the three dimensions; divide by 27 for cubic yards.

Use the regular-polygon area formula with n = 10.

Enter Deck length (ft) board direction, Deck width (ft), and Board width (in) for the Decking Boards Calculator; retain the units printed in each label. The calculator reports Board rows and Linear feet: Rows from board width; linear feet from deck length × rows. Actual board count also depends on gaps, board lengths, cuts, and layout waste.

Enter Wall length (ft), Height (ft), Walls count factor, Waste (%), and Sheet area (ft²) for the Drywall Sheets Calculator; enter percentage fields as percentage points and retain the units printed in each label. The calculator reports Sheets: Sheets = ceil of area×waste / sheet area. Round purchasing quantities up and verify dimensions against site conditions.

Total inches = 12 × feet + inches; then scale to other units.

Enter Fence length (ft), Post spacing (ft), and Rails per section for the Fence Material Calculator; retain the units printed in each label. The calculator reports Posts, Rails, and Panels/sections: Posts from length and spacing; rails per section. Corners, gates, terrain, and end-post rules may require additional materials.

Cost equals area times price per unit area.

Use the regular-polygon area formula with n = 7.

Use the regular-polygon area formula with n = 6.

Total centimeters = 100 × meters + centimeters.

A = π(R² − r²), then apply depth.

V = A × (depth_in / 12); divide by 27 for cubic yards.

A = π((r+w)² − r²).

A = π r², V = A × depth.

A = (ℓ+2w)(W+2w) − ℓW.

A = ℓw, V = A × depth.

A = s², V = A × depth.

A = ½(b₁+b₂)h, then apply depth.

A = ½bh, V = A × depth.

Use the regular-polygon area formula with n = 8.

Enter Perimeter (ft), Height (ft), Coats, and Coverage ft²/gal for the Paint Estimator Calculator; retain the units printed in each label. The calculator reports Area × coats and Gallons: Same coverage model as paint coverage for jobsites. Round purchasing quantities up and verify dimensions against site conditions.

A = (n s²) / (4 tan(π/n)), then C = A × price.

A = ℓw, then C = A × price.

Enter Rise and Run for the Roof Pitch Calculator; use finite values in the indicated domain. The calculator reports Pitch (rise/run) and Angle (°): Pitch is rise/run; angle is arctan of that ratio. Rise and Run must use the same unit, with Run greater than zero.

A = s², then C = A × price.

Enter Total rise (in), Preferred riser (in), and Tread depth (in) for the Stair Stringer Calculator; retain the units printed in each label. The calculator reports Number of risers, Actual rise (in), Treads, and Total run (in): Choose risers near a preferred height and compute treads. Check the resulting riser and tread dimensions against local building codes.

A = ½bh, then C = A × price.