Acres to Hectares Converter

How to convert acres to hectares

An acre is exactly 43,560 square feet. Each square foot is 0.3048 m × 0.3048 m = 0.09290304 m², so an acre is 43,560 × 0.09290304 = 4,046.8564224 m². A hectare is 10,000 m², so dividing gives 0.40468564224 ha per acre. Because both units are areas, the squared foot factor is already built into that number; you never square it again. To go from hectares back to acres, divide by the same number, or let the area converter do it while it also shows square feet, square meters and square miles.

Going the other way, one hectare is about 2.47105 acres. A common slip is to treat hectares and acres as roughly equal. They are not: a hectare is almost two and a half acres, so the number of hectares is always well under half the number of acres. For smaller plots measured in square feet, try the square feet to square meters converter.

You meet this conversion whenever land crosses a border: comparing a US farm listing with European or Canadian prices, reading forestry or crop-yield reports quoted per hectare, or checking a planning document that gives site areas in hectares. Yields and prices per area convert the opposite way to the area itself, so a figure per hectare is about 2.47 times the same figure per acre.

Step by step

1. Take the land area in acres.
2. Multiply by 0.40468564224 (0.4047 is fine for most uses).
3. Round to two or three decimals for property records.

See it on a scale

What is an acre, and what is a hectare?

The acre is a medieval English unit, traditionally the land a team of oxen could plow in a day. It was standardized as one chain by one furlong: 66 ft × 660 ft = 43,560 ft². An acre does not have to be that shape; any area of 43,560 ft² is an acre, whether square (about 208.7 ft per side) or long and thin. It is still the main land unit in the US, and is used for property in the UK, Canada and Australia alongside hectares.

The hectare (ha) is the metric land unit: a square 100 m on each side, or 10,000 m². The name comes from hecto (100) and are, an older metric unit of 100 m². The hectare is not an SI unit, but the SI accepts it for use with SI units, and it is the standard for farmland, forestry and planning in most of the world.

Shortcuts, survey acres and common mistakes

• Acres × 0.4 ≈ hectares. The estimate runs about 1.2% low; 50 ac → 20 ha (exact: 20.23 ha).
• Hectares × 2.5 ≈ acres. About 1.2% high; 10 ha → 25 ac (exact: 24.71 ac).
• Don't mix up hectares and square kilometers. 1 km² = 100 ha = about 247.1 acres.
• Don't use the length factor. Acres are areas; there is no linear “acre”, so feet-to-meters factors never apply directly.

The US survey acre

Older US land records sometimes used an acre based on the US survey foot rather than the international foot. That survey acre is about 4,046.8726 m², roughly 4 parts per million larger, a difference of about 162 cm² per acre. It only matters for very large surveys, and the survey foot was retired at the end of 2022. For distances along a property line, the feet to meters converter applies.