Acre to Hectare Conversion Calculator: Free Online Tool
Convert acres to hectares with our free online area converter.
Acre to Hectare Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Acre).
- The converted value in Hectare will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Area category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Acre to Hectare
Converting Acre to Hectare involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Acre = 0.404686 hectares
Example Calculation:
Convert 10 acres: 10 × 0.404686 = 4.046856 hectares
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Acre and a Hectare?
The acre (symbol: ac) is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet). This is exactly equal to:
- 10 square chains
- 1/640 of a square mile
- 4,840 square yards
- 43,560 square feet
- Approximately 4,046.856 square meters (m²)
- Approximately 0.4047 hectares (ha)
While derived from traditional farming practices, its size is now legally defined based on the international yard.
The hectare (symbol: ha) is a non-SI metric unit of area equal to 10,000 square meters (m²). It is primarily used in the measurement of land. One hectare represents the area of a square with 100-meter sides.
It is equivalent to:
- 1 square hectometer (hm²)
- 100 ares (where 1 are = 100 m²)
- 0.01 square kilometers (km²)
- Approximately 2.471 acres
- Approximately 107,639 square feet (ft²)
The name "hectare" combines the metric prefix hecto- (meaning "hundred") with the unit are.
Note: The Acre is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Hectare belongs to the imperial/US customary system.
History of the Acre and Hectare
- Origin: The word "acre" derives from the Old English word æcer (originally meaning "open field"), cognate with German Acker and Latin ager. It traditionally represented the amount of land that could be ploughed by one man with one yoke of oxen in one day. This practical definition naturally led to considerable variation in its size depending on the land quality and local customs.
- Medieval Variations: Throughout the Middle Ages in England, the acre's size varied. Different regions used "customary acres" based on local practices, often related to the quality of the land or the length of a standard furrow (furlong).
- Standardization (Gunter's Chain): The standardization of the acre is closely linked to the invention of Gunter's chain in 1620. This measuring chain, 66 feet long (divided into 100 links), became a standard survey tool. The traditional definition of an acre as a strip of land one furlong (10 chains or 660 feet) long and one chain (66 feet) wide was easily measured using the chain. This area is precisely 10 square chains.
- Statutory Acre: In England and Wales, the Weights and Measures Act of 1878 formalized the "statutory acre" based on the imperial yard, solidifying the definition as 4,840 square yards (or 43,560 square feet). This is the acre commonly used today in the UK, US, and Commonwealth countries.
- Metrication: Although many countries using the acre have largely adopted the metric system for other measurements, the acre persists strongly in land transactions and agriculture due to historical precedent and cultural familiarity. The hectare (10,000 m²) is the more common metric unit for land.
- Origin (French Revolution): The base unit, the are, was defined in 1795 as 100 square meters as part of the new metric system established during the French Revolution. The hectare ("hundred ares") was created alongside it as a larger, more practical unit for land measurement.
- Adoption: While the are saw some use, the hectare quickly became the preferred metric unit for land transactions and agricultural measurements due to its convenient size, bridging the gap between the square meter and the square kilometer.
- International Recognition: The hectare was adopted by the International Committee for Weights and Measures (CIPM) in 1879. Although the are fell out of favor, the hectare gained widespread international acceptance.
- Status with SI: While the official SI unit of area is the square meter (m²), the hectare is explicitly accepted for use with the International System of Units (SI). Its continued use is recognized due to its global importance in land measurement, agriculture, and forestry.
Common Uses for acres and hectares
Explore the typical applications for both Acre (imperial/US) and Hectare (imperial/US) to understand their common contexts.
Common Uses for acres
The acre remains a primary unit for land measurement in several countries, particularly within specific sectors:
- Real Estate (US, UK, Commonwealth): Standard unit for describing the size of land parcels in property listings, deeds, and surveys, especially for residential lots larger than typical city plots, rural properties, and undeveloped land.
- Agriculture: Widely used by farmers to measure field sizes, calculate crop yields, allocate resources (like fertilizer or seeds), and comply with agricultural regulations.
- Land Management and Planning: Used in zoning regulations, environmental assessments, and land development projects to specify area requirements or limitations.
- Historical Documents: Understanding the acre is crucial for interpreting historical land records, surveys, and deeds.
- Informal Comparisons: Often used informally to help visualize the size of large areas, even where metric units are officially standard.
Common Uses for hectares
The hectare is the principal metric unit for land area measurement in many fields globally:
- Agriculture: Standard unit worldwide for measuring farm sizes, field areas, crop yields, and agricultural statistics (e.g., FAO reports).
- Forestry: Used for measuring forest extents, logging areas, and managing timber resources.
- Urban Planning and Land Management: Employed in zoning regulations, measuring park sizes, planning large-scale developments, and conducting environmental impact assessments across most metricated nations.
- Real Estate: The standard unit for large land parcels in most countries (though acres may persist alongside it in some Commonwealth nations transitioning from imperial).
- International Law and Treaties: Often used in legal definitions of land boundaries and resource allocation agreements (e.g., within the European Union).
Frequently Asked Questions
Questions About Acre (acre)
How big is an acre visually?
An acre is 43,560 square feet. While it can be any shape, a square acre would be about 208.71 feet on each side. A common visual comparison is an American football field: one acre is about 90.75% of the total area of a standard American football field (which is 120 yards long by 53.33 yards wide, or 57,600 sq ft including end zones). Excluding the end zones (100 yards by 53.33 yards, or 48,000 sq ft), an acre is about 90.75% of the playing field area.
How many square feet are in an acre?
There are exactly 43,560 square feet in one acre. This definition (1 furlong × 1 chain = 660 ft × 66 ft) is precise.
How many square yards are in an acre?
There are exactly 4,840 square yards in one acre (since 1 yard = 3 feet, 1 square yard = 9 square feet; 43,560 / 9 = 4,840).
How many acres are in a square mile?
There are exactly 640 acres in one square mile.
How many acres are in a hectare?
One hectare is equal to 10,000 square meters. Since one acre is approximately 4,046.856 square meters, one hectare contains approximately 2.471 acres (10,000 / 4046.856 ≈ 2.471). Conversely, one acre is approximately 0.4047 hectares.
Is the acre an SI unit?
No, the acre is not part of the International System of Units (SI). It belongs to the imperial and US customary systems. The SI unit for area is the square meter (m²). For land measurement, the hectare (ha), equal to 10,000 m², is commonly used in metric contexts and is accepted for use with SI.
About Hectare (ha)
How large is a hectare visually?
A hectare is 10,000 square meters. A square hectare is 100 meters by 100 meters. For comparison:
- It's slightly smaller than an international rugby union pitch (max 100m x 70m = 7,000 m²).
- It's about 1.4 times the size of a standard FIFA football (soccer) pitch (recommended 105m x 68m = 7,140 m²).
- London's Trafalgar Square is roughly one hectare in area.
- An American football field (including end zones) is about 0.535 hectares.
How many square meters are in a hectare?
There are exactly 10,000 square meters (m²) in one hectare (ha).
What is an "are" and how does it relate to a hectare?
The are (symbol: a) is another metric unit of area defined as 100 square meters (a square 10 meters by 10 meters). It was part of the original metric system. A hectare is equal to 100 ares. The are itself is rarely used today, but the hectare remains very common.
How many acres are in a hectare?
One hectare is approximately 2.471 acres. To convert hectares to acres, multiply by 2.471. Conversely, 1 acre is about 0.4047 hectares.
How many hectares are in a square kilometer?
There are exactly 100 hectares in one square kilometer (km²). This is because 1 km² = 1,000,000 m² and 1 ha = 10,000 m², so 1,000,000 / 10,000 = 100.
Is the hectare an official SI unit?
No, the hectare (ha) is not a base or derived unit within the International System of Units (SI). The SI unit for area is the square meter (m²). However, the hectare is listed by the International Bureau of Weights and Measures (BIPM) as a non-SI unit accepted for use with the SI due to its widespread practical importance, particularly in land measurement.
Conversion Table: Acre to Hectare
Acre (acre) | Hectare (ha) |
---|---|
1 | 0.405 |
5 | 2.023 |
10 | 4.047 |
25 | 10.117 |
50 | 20.234 |
100 | 40.469 |
500 | 202.343 |
1,000 | 404.686 |