Acres to Hectares Converter

The exact figures

A hectare is defined simply: 10,000 square metres, a square 100 metres on each side. The acre is not simple at all. It is 4,840 square yards, or 43,560 square feet, and it descends from the area a man with one ox could plough in a day — historically a strip one furlong long by one chain wide.

That is why the acre is a long thin rectangle by origin rather than a square: ploughing favoured long runs because turning the ox was slow. The furlong itself survives in horse racing, and a chain is 22 yards, which is why a cricket pitch is 22 yards long.

Making the numbers mean something

An acre is roughly the size of a standard football pitch minus the end zones, or about 60% of a full-size FIFA pitch. A hectare is close to two and a half acres, or roughly one and a half football pitches.

A rough conversion that works for mental arithmetic: acres to hectares, divide by two and a half. Hectares to acres, multiply by two and a half. That is accurate to within about 1%, which is well inside the precision of most land descriptions anyway.

Where each unit is used

Hectares are standard for agricultural and land-use statistics almost everywhere, including in the UK, where farm subsidies and land registry entries use them despite farmers frequently still thinking in acres. The United States uses acres throughout, and US land descriptions are built on them: a section is 640 acres, a quarter-section 160.

Those figures are not arbitrary. The Public Land Survey System divided much of the country into six-mile-square townships of 36 sections, and the 160-acre quarter-section was the standard homestead grant. Rural American property boundaries still follow that grid, which is why so many state and county lines are straight.

Reading land listings carefully

Two cautions. First, land area is usually measured on the horizontal plane rather than following the ground surface, so ten acres of steep hillside has more actual surface than ten acres of flat field but is described identically. Second, stated areas frequently include unusable portions — watercourses, easements, access strips, setbacks — so the buildable or farmable area can be considerably smaller than the headline figure.

For smaller plots, gardens and building footprints, the square feet to square metres converter is the more useful tool, since areas below about a quarter of an acre are more naturally described in square units.

Frequently asked questions