US Construction Unit Conversion Chart
A practical construction conversion reference for inches, feet, square feet, cubic yards, US gallons, pounds, PSI and common metric units.
US construction work often mixes customary and metric measurements. Drawings may use feet and inches, equipment data may use PSI, and a product sheet may list millimeters or liters. Convert the quantity by category—length, area, volume, mass or pressure—and never use a linear factor for an area or volume.
Quick length conversions
| From | To | Factor | | --- | --- | ---: | | inches | millimeters | × 25.4 | | feet | meters | × 0.3048 | | yards | meters | × 0.9144 | | miles | kilometers | × 1.609344 |
The international foot is exactly 0.3048 meter. For routine building dimensions, that is the foot used in the conversion. Historical survey records may require different treatment.
Area conversions
| From | To | Factor | | --- | --- | ---: | | square feet | square meters | × 0.09290304 | | square yards | square meters | × 0.83612736 | | acres | square feet | × 43,560 |
Do not multiply square feet by 0.3048. That is a length factor. Area factors are squared because both dimensions are converted.
Volume conversions
| From | To | Factor | | --- | --- | ---: | | cubic feet | cubic meters | × 0.0283168 | | cubic yards | cubic feet | × 27 | | cubic yards | cubic meters | × 0.764555 | | US gallons | liters | × 3.78541 |
US liquid gallons and UK imperial gallons are different. A supplier specification that says only “gallons” needs context before conversion.
Weight and pressure
| From | To | Factor | | --- | --- | ---: | | pounds | kilograms | × 0.453592 | | US short tons | pounds | × 2,000 | | PSI | kilopascals | × 6.89476 |
Check whether “ton” means a US short ton, metric tonne or UK long ton. They are not interchangeable.
A safe conversion workflow
- Identify the kind of quantity: length, area, volume, weight, temperature or pressure.
- Record the source unit exactly.
- Use enough precision for the purpose.
- Convert once from the original value.
- Round only the displayed or ordering result.
- Keep the original value beside the conversion so somebody else can check it.
Open the US construction unit converter for length, area, volume, weight, temperature, pressure and speed conversions.
The factors above align with NIST’s approximate US customary-to-metric reference and Guide to the SI conversion factors. For fabrication, surveying, engineering or code work, use the precision and source required by the project—not a rounded pocket reference.