Construction Quantity Unit Conversions
Length, area, volume and US short-ton conversions for checking quantity schedules.
Match dimensions before converting
A linear measure cannot be converted to an area or volume without additional dimensions. Write the input unit beside each measurement, and retain enough precision until the final schedule.
| Conversion | Relationship | | --- | --- | | Inches to feet | FT = IN ÷ 12 | | Square inches to square feet | SF = square inches ÷ 144 | | Cubic feet to cubic yards | CY = cubic feet ÷ 27 | | Rectangular area | SF = length in FT × width in FT | | Uniform slab volume | CY = length FT × width FT × thickness IN ÷ 12 ÷ 27 | | Roofing squares | Squares = measured roof SF ÷ 100 | | Pounds to US short tons | Short tons = LB ÷ 2,000 |
Worked dimensional example
A uniform 30 FT × 20 FT slab at 6 IN thickness has a geometric volume of 30 × 20 × 0.5 = 300 cubic feet, or 11.111 CY before any user-selected allowance. This excludes beams, foundations and thickened edges. Use the concrete quantity calculator to change these inputs.
Quantity review checks
Keep short tons distinct from metric tonnes. Keep bank, loose and compacted earth volumes distinct: a unit conversion does not establish a soil adjustment factor. Confirm whether roof area is measured on the roof plane. Identify rounding and purchasing conventions separately from geometric quantities.
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