A Guide to Land & Space Units

Area measurements are vital, but the units can vary dramatically by region and application.

Large-Scale Land: Acre vs. Hectare

Acre (ac): An imperial unit, an acre was historically the amount of land one man with one ox could plow in a day. It's widely used for land in the US and is equal to 43,560 ft².

Hectare (ha): A metric unit, its name comes from the Greek "hecto" (hundred). A hectare is a square with 100-meter sides (10,000 m²). It's the standard for most of the world and is roughly 2.47 acres.

Specialized Units

Roofing Square: In the US construction industry, a "square" is a unit of area for roofing materials, equal to 100 square feet (ft²).

Section: Used in the US land survey system, a section is one square mile, or 640 acres. This is fundamental to land titles in much of the US.