¿Qué es un/una Hectare (ha)?
The hectare (symbol: ha) is a non-SI metric unit of area equal to 10,000 square meters (10⁴ m²), or equivalently 100 ares, or 0.01 square kilometers. The word is formed from the SI prefix "hecto-" (meaning 100) and the unit "are" (a metric unit equal to 100 square meters). A hectare is the area of a square with sides of exactly 100 meters.
Although the hectare is not an SI unit, it is accepted for use with the International System of Units by the International Bureau of Weights and Measures (BIPM). The SI brochure states that the hectare may be used alongside SI units and acknowledges its widespread practical importance in land measurement. One hectare is equivalent to approximately 2.47105 acres, making it roughly two and a half times the size of an acre.
Practical Scale for Land Measurement
The hectare provides a practical, human-scaled unit for expressing land areas. Agricultural fields, urban parks, forest plots, and residential developments are all conveniently described in hectares. Areas that would require five- or six-digit numbers in square meters, or unwieldy decimal fractions in square kilometers, fall neatly into single- or double-digit hectare values. A typical European farm might be 50-200 hectares, a city park might be 5-50 hectares, and a national forest might span thousands of hectares.
The are (100 m²) and its submultiple the centiare (1 m²) are occasionally used in land registration and real estate in some countries, particularly in France and Belgium, but the hectare dominates practical land measurement worldwide. The decare (1,000 m², or 0.1 hectares) is used in Turkey, Bulgaria, and some other countries as a unit of agricultural land area.
Etymology
Greek and Latin Components
The word "hectare" is a compound of two elements: "hect-" (a contraction of "hecto-," from the Greek "hekaton" meaning "hundred") and "are" (from the Latin "area," meaning an open, level space or ground). The hectare is thus literally "one hundred ares," where each are is 100 square meters. The resulting unit of 10,000 square meters was given the name "hectare" during the establishment of the French metric system.
The Are and the Prefix System
The base unit "are" was coined by the French revolutionary commission that created the metric system in the 1790s. The Latin word "area" had long been used in European languages to refer to a piece of flat ground or a threshing floor, and it was adopted as the name for the metric unit of land area. The prefix system — deca- (10), hecto- (100), kilo- (1000) — was applied to create larger units: the decare (1,000 m²), the hectare (10,000 m²), and the theoretically possible kiloare (1,000,000 m², though this was never used since the square kilometer fills the same role).
An Artificial Construction
The spelling "hectare" reflects French pronunciation conventions, where the original "hectoare" was shortened for ease of use. The abbreviation "ha" was adopted as the standard symbol and is used internationally without variation. Unlike many measurement terms that evolved organically from practical use, "hectare" is an entirely artificial word, deliberately constructed from Greek and Latin roots during the rationalization of measurement that accompanied the French Revolution.
Precise Definition
The hectare is defined as exactly 10,000 square meters, equivalent to the area of a square with sides of 100 meters. In derived SI units, one hectare equals 0.01 square kilometers or 100 ares. The hectare is a non-SI unit that is officially accepted for use with the International System of Units by the International Bureau of Weights and Measures (BIPM), as stated in the 9th edition of the SI Brochure.
BIPM Acceptance and Practical Use
The BIPM acceptance means that while the hectare is not part of the SI system proper (the SI unit of area is the square meter), it may be used in conjunction with SI units in scientific and technical publications. The BIPM specifically notes the hectare's importance in land measurement, where expressing areas in square meters would yield unwieldy numbers — a modest farm of 50 hectares would be 500,000 square meters, for example.
Imperial and Customary Equivalents
In terms of imperial and US customary equivalents, one hectare equals approximately 2.47105 acres, or approximately 107,639 square feet, or approximately 11,960 square yards. One square mile contains approximately 259 hectares. These conversions are not exact because the acre and other imperial area units are defined through the international foot (0.3048 meters), yielding irrational conversion factors when expressed in hectares.
Historia
The French Revolution and the Metric System
The hectare originated as part of the French metric system, which was first introduced during the French Revolution. The revolutionary government sought to replace the bewildering variety of local measurement units that existed across France — there were reportedly over 800 different units of area in use — with a rational, decimal-based system derived from natural constants. The metric system was formally adopted by France in 1795 through the law of 18 Germinal, Year III of the Republican Calendar (April 7, 1795).
The original metric system of 1795 defined the "are" as the fundamental unit of area, equal to the area of a square with sides of 10 meters (100 square meters). The standard metric prefixes were applied to create multiples: the decare (10 ares, 1,000 m²), the hectare (100 ares, 10,000 m²), and so on. In practice, the hectare quickly emerged as the most useful of these derived units because its size corresponded well to the scale of agricultural fields and land parcels.
Napoleonic Spread Across Europe
During the Napoleonic era and the early 19th century, the metric system — including the hectare — spread beyond France to Belgium, the Netherlands, Luxembourg, and parts of Germany and Italy. Napoleon's conquests carried the metric system across much of Europe, though some conquered territories reverted to traditional units after his defeat. Nevertheless, the advantages of a decimal measurement system were widely recognized, and voluntary adoption continued throughout the 19th century.
The SI System and Official Recognition
When the International System of Units (SI) was established in 1960 by the 11th General Conference on Weights and Measures (CGPM), the hectare was not included as an SI unit. The SI system uses the square meter as its unit of area, with standard SI prefixes for multiples (square kilometer, etc.). However, the CGPM recognized the practical importance of the hectare and officially accepted it for use alongside SI units — a status it retains today.
Replacing Traditional Land Units Worldwide
The hectare gradually replaced local land measurement units around the world during the 19th and 20th centuries as countries adopted the metric system. It replaced the acre in most Commonwealth countries during metrication (Australia in the 1970s, India progressively from the 1950s, South Africa in the 1970s). It replaced the morgen in Germany and South Africa, the manzana in Central America, the jerib in Afghanistan, and countless other traditional land units across Asia, Africa, and the Americas.
In the European Union, the hectare became the standard unit for agricultural policy when the Common Agricultural Policy (CAP) adopted it for calculating farm subsidies, production quotas, and land-use statistics. The Food and Agriculture Organization (FAO) of the United Nations uses hectares as the global standard for reporting agricultural land areas, crop yields (typically expressed as tonnes per hectare), and deforestation rates.
Today the hectare is the standard unit for land measurement in the cadastral (land registry) systems of virtually every metric country. The major exceptions are the United States, where the acre is used in land records, real estate, and agriculture, and the United Kingdom, where acres remain the common unit for land area in everyday use despite official metrication. Even in these countries, hectares appear in scientific publications, environmental reporting, and international communications.
Uso actual
Global Agriculture and Environment
The hectare is used globally as the primary unit for measuring land area in agriculture, forestry, urban planning, and environmental science. Agricultural production statistics, crop yields (expressed as tonnes per hectare), and land-use data are reported in hectares by international organizations including the FAO, the World Bank, the European Union, and national statistical agencies worldwide. Global deforestation is tracked in hectares — the Amazon rainforest, for example, has lost an estimated 17% of its forest cover, representing tens of millions of hectares.
Real Estate and Zoning
In countries that use the metric system, real estate land areas are typically expressed in hectares for larger properties and square meters for smaller ones. A residential lot might be described as 500 m², while a farm would be described as 120 hectares, and a national park as 50,000 hectares. Zoning regulations, environmental impact assessments, and conservation area designations use hectares as the standard unit across Europe, Asia, Africa, and most of the Americas.
The European Union's Common Agricultural Policy (CAP), which distributes billions of euros in farm subsidies annually, uses hectares as its fundamental unit for calculating payment eligibility and rates. Farmers across the EU report their cultivated area in hectares, and subsidy payments are calculated on a per-hectare basis. The EU's Land Parcel Identification System (LPIS) maps every agricultural parcel in the union using hectare-based measurements.
Exceptions: The US and UK
The major exceptions to hectare dominance are the United States and the United Kingdom. In the US, the acre remains the primary unit for land measurement in real estate, agriculture, and government land management. US farmers discuss their operations in acres, and land is bought and sold by the acre. In the UK, acres are used in everyday speech and real estate listings, though hectares appear in official government statistics and scientific publications. Canada officially uses hectares following metrication, but acres persist in informal use, particularly in real estate in English-speaking provinces.
Everyday Use
For people in metric countries, the hectare is the natural unit for understanding land area at the human scale. When someone says "a 2-hectare property" or "a 50-hectare farm," the listener immediately grasps the approximate size. Newspaper reports about land development, conservation areas, or agricultural production routinely use hectares, and most adults in metric countries have an intuitive sense of how large a hectare is.
Visualizing a Hectare
Visual comparisons help convey the size of a hectare to those less familiar with the unit. A standard FIFA football (soccer) pitch ranges from 0.62 to 0.82 hectares (the pitch dimensions are variable within FIFA's rules, typically 100-110 m long by 64-75 m wide). A regulation rugby union pitch including in-goal areas is approximately 1.008 hectares. The playing area of an American football field (including end zones) is approximately 0.535 hectares. So a hectare is roughly the size of a large sports field — an accessible mental image.
Real Estate and Land Value
In real estate, the hectare defines property values and development potential. Agricultural land prices are quoted per hectare in most of the world — from the fertile plains of France (averaging around 6,000-8,000 euros per hectare for cropland) to the vast pastoral lands of Australia (where prices can range from under 500 to over 10,000 AUD per hectare depending on location and rainfall). Urban planning regulations specify density limits in dwellings per hectare, and housing developments are planned and marketed with hectare-based area specifications.
Environmental Communication
Environmental communication relies heavily on hectares. News stories about wildfires, deforestation, and land conservation almost always cite areas in hectares. The 2019-2020 Australian bushfire season burned approximately 18.6 million hectares. The Amazon loses hundreds of thousands of hectares of forest per year. National parks and nature reserves are described in hectares: Yellowstone National Park covers approximately 898,000 hectares, Kruger National Park in South Africa spans approximately 1,898,000 hectares, and the Great Barrier Reef Marine Park encompasses approximately 34,440,000 hectares.
In Science & Industry
Forestry and Ecology
In forestry and ecology, the hectare is the standard unit for describing forest cover, habitat area, and ecosystem extent. Forest inventories measure standing timber volume in cubic meters per hectare, and carbon sequestration rates are expressed in tonnes of CO₂ per hectare per year. A mature tropical forest typically stores 150-300 tonnes of carbon per hectare in its biomass, making hectare-based measurements essential for climate change research and carbon credit calculations.
Agriculture and Agronomy
In agriculture and agronomy, crop yields are universally reported in tonnes (or kilograms) per hectare. Global wheat yields average approximately 3.5 tonnes per hectare, rice yields average about 4.7 tonnes per hectare, and corn (maize) yields in highly productive regions like the US Corn Belt can exceed 10 tonnes per hectare. These per-hectare yield figures are fundamental to food security analysis, agricultural economics, and policy planning. Fertilizer application rates, pesticide dosages, and irrigation requirements are also specified per hectare.
Remote Sensing and Land Surveying
Land surveying and cadastral science use the hectare as the primary unit for parcel areas in most countries. Geographic Information Systems (GIS) calculate and display land areas in hectares for parcels above a certain size. Remote sensing and satellite imagery analysis report land cover changes in hectares — deforestation rates, urban expansion, wetland loss, and desertification are all tracked using hectare-based measurements. The European Space Agency's Copernicus Land Monitoring Service and NASA's Landsat program provide data that is typically analyzed and reported in hectare units.
Urban Planning and Density
In urban planning and transportation, the hectare serves as the basis for density calculations that shape cities. Residential density is expressed as dwellings per hectare (or people per hectare), with low-density suburban areas at 10-30 dwellings per hectare and high-density urban cores at 100-300+ dwellings per hectare. Floor area ratios, green space requirements, and infrastructure capacity planning all reference hectare-based density metrics. The World Health Organization recommends a minimum of 9 square meters of green space per capita, which translates to hectare-level planning for parks and open spaces in urban areas.
Multiples & Submultiples
| Name | Symbol | Factor |
|---|---|---|
| Centiare (1 m² — one square meter, used in land registration) | ca | 0.0001 |
| Are (100 m² — base unit, rarely used alone) | a | 0.01 |
| Decare (1,000 m² — used in Turkey, Bulgaria, Norway) | daa | 0.1 |
| Hectare (10,000 m² — the standard practical unit) | ha | 1 |
Interesting Facts
A standard FIFA football (soccer) pitch at its maximum dimensions (110 × 75 meters) is 0.825 hectares, so a hectare is slightly larger than the largest allowed football pitch.
Central Park in New York City covers approximately 341 hectares (843 acres), making it about 6% of the total area of Manhattan island (5,910 hectares).
The Vatican City, the world's smallest independent state, has a total area of approximately 44 hectares (0.44 km²) — roughly the size of a medium-large farm.
The world's total agricultural land is approximately 4.8 billion hectares, of which about 1.5 billion hectares is arable cropland and 3.3 billion hectares is permanent pasture, according to FAO data.
A single hectare of tropical rainforest can contain over 400 tree species and store approximately 200 tonnes of carbon in its biomass — equivalent to the annual CO₂ emissions of about 40 average cars.
The largest single farm in the world, Anna Creek Station in South Australia, covers approximately 2,400,000 hectares (24,000 km²) — larger than the entire country of Israel.
One hectare of wheat in a productive region yields approximately 8-10 tonnes of grain, enough to produce roughly 12,000-15,000 loaves of bread.
The Amazon rainforest covers approximately 550 million hectares, roughly the size of the contiguous United States west of the Mississippi River.
Luxembourg, one of Europe's smallest countries, has a total area of approximately 259,000 hectares, while a large Australian cattle station can exceed 500,000 hectares.
Urban density in Hong Kong reaches approximately 400 people per hectare in its densest districts, while suburban American sprawl typically houses only 15-25 people per hectare — a roughly 20-fold difference.
Regional Variations
United States
The hectare is the dominant unit of land measurement in virtually every country that uses the metric system, but alternative units persist in certain regions. In the United States, the acre (approximately 0.4047 hectares) is the standard unit for all land measurement purposes — real estate, agriculture, forestry, and government land management all use acres. US farmers speak of "160 acres" rather than "65 hectares," and land prices are quoted per acre. The acre is legally defined in every US state and is embedded in property records dating back centuries.
United Kingdom
In the United Kingdom, the acre remains the common unit for land area in everyday life and real estate, despite the UK's official adoption of the metric system. Estate agents (realtors) list properties in acres, farmers discuss their holdings in acres, and the general public thinks in acres rather than hectares. However, official UK government statistics, scientific publications, and EU-related reporting use hectares, creating a dual system that parallels the UK's use of miles on road signs alongside metric measurements elsewhere.
Local Variants Around the World
Several countries use unique local variants alongside or instead of the standard hectare. In Turkey, the decare (dönüm, equal to 1,000 m² or 0.1 hectares) is the common unit for agricultural land. In Bulgaria and some other Balkan countries, the decare is similarly preferred for everyday land measurement. In Thailand, the rai (1,600 m² or 0.16 hectares) remains the standard unit for land measurement. In Japan, the tsubo (approximately 3.31 m²) and the older tan (approximately 991.7 m² or about 0.1 hectare) are still used in real estate alongside metric measurements. In Brazil, the alqueire varies by region from about 2.4 to 4.8 hectares, though official records use hectares.