Acres vs Hectares: Area Units Compared
Key Difference
1 hectare = 2.471 acres. A hectare is exactly 10,000 square meters (100 m × 100 m). An acre is 43,560 square feet, roughly the size of a football field. Hectares are used internationally while acres dominate in the US and UK.
Side-by-Side Comparison
| Property | Acre (ac) | Hectare (ha) |
|---|---|---|
| Symbol | ac | ha |
| System | Imperial / US Customary | Metric (SI-accepted) |
| In square meters | 4,046.86 m² | 10,000 m² |
| In square feet | 43,560 ft² | 107,639 ft² |
| Used in | USA, UK, Canada (informal) | Most countries worldwide |
| Common uses | Real estate, farming, forestry | Agriculture, forestry, land planning |
| Conversion | 1 ac = 0.404686 ha | 1 ha = 2.47105 ac |
Where Each Is Used
Acres are the standard land area unit in the United States, used for real estate listings, farm sizes, zoning regulations, and property tax assessments. The UK uses acres extensively in real estate and agriculture. Canada and Australia use acres informally, especially in rural real estate, despite officially adopting hectares.
Hectares are used by the United Nations Food and Agriculture Organization (FAO) for agricultural statistics, by governments worldwide for land use planning, and in environmental science for forest coverage and conservation areas. All European, Asian, African, and South American countries use hectares as their official land area unit.
International conservation organizations report habitat areas in hectares. When you read that a national park covers “200,000 hectares,” that equals about 494,000 acres or roughly 2,000 square kilometers.
Conversion Formulas
Acres to Hectares
ha = ac × 0.404686
Example: 100 ac = 100 × 0.404686 = 40.47 ha
Hectares to Acres
ac = ha × 2.47105
Example: 50 ha = 50 × 2.47105 = 123.55 ac
Quick Reference Table
| Acres | Hectares | Context |
|---|---|---|
| 0.25 | 0.10 | Large residential lot |
| 1 | 0.40 | Football field (approx.) |
| 5 | 2.02 | Small hobby farm |
| 10 | 4.05 | Small farm |
| 40 | 16.19 | Quarter section (US) |
| 100 | 40.47 | Medium farm |
| 640 | 259.00 | 1 square mile (section) |
When to Use Which
Use acres when working with US or UK real estate, American agriculture, or reading US property records. Land surveys, property deeds, and zoning in the US are all in acres.
Use hectares for international communication, scientific reporting, environmental conservation data, and when working with metric countries. The EU Common Agricultural Policy reports farm sizes in hectares.
Quick mental shortcut: multiply acres by 0.4 to get a rough hectare estimate, or multiply hectares by 2.5 to get approximate acres. For example, 200 acres × 0.4 = 80 hectares (actual: 80.94).
A Brief History
The acre originated in medieval England as the amount of land a yoke of oxen could plow in a day. It was defined as a strip 1 furlong long (660 feet) by 1 chain wide (66 feet), giving 43,560 square feet. This practical agricultural origin explains its irregular relationship with other imperial units. The word comes from the Old English “æcer,” meaning open field.
The hectare was introduced with the metric system in 1795, defined as 10,000 square meters (a square 100 m on each side). The prefix “hecto-” means one hundred, and “are” is a metric unit of 100 square meters, so a hectare is 100 ares. Its clean decimal relationship makes it straightforward for calculations and conversions.