Convert ha to km² hectares ↔ square kilometres Free Online Secure
Type a value in hectares and read it in square kilometres at once. The factor is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Common values — Convert ha to km² (hectares ↔ square kilometres)
| ha | km² |
|---|---|
| 1 | 0.01 |
| 2 | 0.02 |
| 3 | 0.03 |
| 5 | 0.05 |
| 10 | 0.1 |
| 20 | 0.2 |
| 50 | 0.5 |
| 100 | 1 |
Where these units come from
Square units need no definition of their own: a square metre is a metre by a metre, and everything follows from the length. The land measures are older and stranger. The acre began as the land a yoke of oxen could plough in a day, which is why it was long and thin rather than square — one chain by one furlong, 4840 square yards. The hectare and the are came out of the French Revolution, when land had to be measured in something decimal; neither belongs to the International System, but both were kept for land because a hectare is a comfortable size to picture and a square metre is not. Since the 1959 agreement on the yard, the acre is exactly 4046.8564224 square metres, so the conversions on this page are exact rather than approximate.
Where you meet them
Square metres price flats, size carpets and decide how much paint a wall needs; square feet do the same work in the United States and in much of the property market worldwide. Hectares belong to farmland, forests and planning permissions; acres to land deeds in the English-speaking world. Square kilometres and square miles are for countries, lakes and fires. Square centimetres and square millimetres live in workshops, on datasheets and anywhere a cross-section matters.
Questions people ask
How big is a hectare, really?
A hectare is a square of 100 m by 100 m, which is 10,000 square metres or about 2.47 acres. A full-size football pitch, touchline to touchline, is roughly 0.7 of a hectare, so a hectare is a pitch and a half. The are, now rarely used on its own, is a hundredth of that: 100 square metres, a square ten metres on a side.
How big is a square kilometre?
A square one kilometre on each side, which is 100 hectares or 1,000,000 square metres. Central Park in New York covers about 3.4 square kilometres, and the whole of Monaco about 2. It is the natural unit for countries, lakes, forests and cities, where the figures in square metres would run to many digits.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
When hectares pile up, square kilometres take over
A hectare is a handy unit for a field, but once a number reaches thousands the eye gets tired. A national park of 898,000 hectares, a fire of 930,000, a forest of 2.5 million: such figures are usually restated in square kilometres, where they become 8,980, 9,300 and 25,000. To convert ha to km² you divide by 100, because a square kilometre contains exactly 100 hectares, a square of ten hectares by ten. This page divides as you type, and the text below shows where the conversion matters, from wildfires and wind farms to the vineyards of Bordeaux.
You will find the rule with worked examples, short profiles of the two units, a comparison, a long tour of real situations and a list of the mistakes people make most often. The calculation runs in your browser and nothing you type leaves your device.
How to convert ha to km²: divide by 100
The rule
One square kilometre equals exactly 100 hectares. To convert ha to km², divide the number of hectares by 100, which means moving the decimal point two places to the left. So 500 ha is 5 km², 12,500 ha is 125 km² and 2.5 million ha is 25,000 km². To go back, multiply square kilometres by 100.
Worked examples
A nature reserve of 3,400 ha is 34 km². A county of 87,000 ha is 870 km². A vineyard region of 110,000 ha is 1,100 km². When the number of hectares is below 100, the answer is a fraction: 40 ha is 0.4 km², and 5 ha is 0.05 km².
Why it is easy
A side of one kilometre is 10 hectometres long, and a hectometre is 100 metres, so a square kilometre is 10 by 10 squares of one hectare. That gives 100, a power of ten, and no arithmetic is needed beyond moving the decimal point.
A quick check
The square kilometre is the big unit, so the number must get smaller by two digits. If your “convert ha to km²” calculation produced a bigger number than you began with, you multiplied instead of dividing.
The hectare
Ten thousand square metres
The hectare is a square of 100 by 100 metres, 10,000 m². The name was coined in 1795 from hecto, hundred, and are. It is accepted for use with the SI and is the standard unit for land in agriculture, forestry and conservation. A hectare is a little over two and a half acres.
Where it is used
Farms, orchards, forests, reserves and building estates are described in hectares in almost every country that uses the metric system. Statistical offices publish land use in hectares, and farm subsidies are paid per hectare.
The square kilometre
One million square metres
The square kilometre is the area of a square 1000 metres on a side. It equals 100 hectares, one million square metres, or 0.386 square miles. It is the unit for countries, regions, large lakes and cities. Population density is stated in people per square kilometre.
Where it is used
Atlases, encyclopaedias, news reports and official statistics use square kilometres for any area larger than a few hundred hectares.
Hectare and square kilometre compared
A square kilometre holds a hundred hectares. The hectare suits fields, the square kilometre districts and countries. Choose the unit that keeps the number between about 1 and 1,000: 50 hectares reads better than 0.5 km², but 25,000 km² reads better than 2.5 million hectares.
The conversion is a pure shift of the decimal point, so it carries no rounding risk. The risk is only that readers mistake one unit for the other, which is why articles that mix both should state the unit with every number.
Where the conversion appears
Wildfires and deforestation
The Australian bushfires of 2019 and 2020 burned about 18.6 million hectares, 186,000 km², larger than the whole of England and Wales together. Brazil's Amazon lost about 1.1 million hectares in a year, 11,000 km². Reports from different agencies use different units, so a “convert ha to km²” calculation is the first step to compare them.
Cities and parks
Paris covers 10,540 ha, 105.4 km². Monaco covers 202 ha, 2.02 km². The Lake Constance region has 53,600 ha of water, 536 km². A traveller reading guidebooks from different countries may meet all three units in a week.
Energy projects
The Hornsea One offshore wind farm occupies 40,700 ha of sea, 407 km². The Bhadla solar park in India covers 5,700 ha, 57 km². Energy companies describe project sites in hectares, and regulators in square kilometres.
European farmland
The farmland of the European Union covers roughly 157 million ha, 1.57 million km², about 39 per cent of its territory. France has 29 million ha, 290,000 km², and Romania 14.5 million ha, 145,000 km². Agricultural statistics often use hectares for individual farms and square kilometres when comparing countries.
Industrial and logistics sites
A large port may cover 1,000 to 5,000 ha, 10 to 50 km². The port of Rotterdam occupies 12,600 ha, 126 km². The Jebel Ali free zone near Dubai covers 14,000 ha, 140 km². Planners compare these sites with cities, and a “convert ha to km²” calculation is the quickest way to do it.
Urban sprawl
The built up area of Greater London is about 160,000 ha, 1,600 km². New York's urbanised area is about 880,000 ha, 8,800 km². A city that grows by 1,000 ha a year adds 10 km² annually, and urban geographers describe growth in both units depending on the audience.
Farm structure
A farm of 50 ha is 0.5 km². A district with 2,000 such farms covers 100,000 ha, 1,000 km², if all the land is farmed. Agricultural economists move between these scales when they study how many farms a region supports.
Precision and rounding
The conversion is exact, so rounding is only for presentation. State square kilometres with as many decimals as the source: 1,234 ha is 12.34 km², not 12 km². If the source says about 1,200 ha, say about 12 km².
Spreadsheet use
Write hectares in column A and =A2/100 in column B. For the reverse, use =B2*100. Format square kilometres with two decimals. For a table with many regions, add a total and compare it with the figure for the whole country.
Teaching the idea
Mark a square of 100 by 100 metres in the playground and call it a hectare. Then show on a map that a square kilometre is ten of these squares on each side, 100 in all. A grid of ten by ten coloured squares on paper makes the same point.
Maps, scales and measurement
On a map with a scale of 1:50,000, one centimetre represents 500 metres, and a square centimetre represents 25 ha, 0.25 km². A map sheet of 40 by 30 cm covers 3,000 ha, 30 km². Cartographers use both units to describe sheet coverage.
Environmental impact reports
Impact statements describe the land affected in hectares, and the region in square kilometres. A project that disturbs 250 ha in a district of 80,000 ha affects 0.31 per cent, which is 2.5 km² of 800 km². The proportion is the same in both units, but the numbers are easier to read in one.
Land use statistics
National land use tables split a country into farmland, forest, built up area, water and other uses, and give each in thousands of hectares. A country of 50 million ha has, say, 24 million ha of farmland, 17 million ha of forest and 3 million ha of built up land. Turn each into square kilometres by dividing by 100 and you get 240,000, 170,000 and 30,000 km², figures that match the way atlases and international comparisons are expressed. A “convert ha to km²” calculation on each line of the table gives a consistent presentation.
Fire danger and burned area
Fire services report burned area in hectares because crews work on the ground, while scientists who study satellite images report square kilometres. A fire of 15,000 ha is 150 km², about the size of a mid sized city. Each year the European Forest Fire Information System publishes burned area in hectares by country, and its mapping partners restate the totals in square kilometres for the public.
The vineyards of Bordeaux
The Bordeaux wine region has about 110,000 ha of vines, 1,100 km². France as a whole has about 800,000 ha, 8,000 km², and Spain 950,000 ha, 9,500 km². Wine statistics from the OIV are in hectares, while maps showing wine regions give their sizes in square kilometres.
Glaciers, ice and snow cover
The area of the Aletsch Glacier in Switzerland is about 8,000 ha, 80 km². Mount Kilimanjaro's ice has shrunk from 1,200 ha in 1912 to under 200 ha today, from 12 km² to less than 2. Glaciologists write ice cover in square kilometres in scientific papers, but local reports of retreat sometimes use hectares, so the conversion is a daily tool for those who follow climate stories.
Marine protected areas
Ocean reserves are enormous. The Papahānaumokuākea Marine National Monument in Hawaii covers about 150 million ha, 1.5 million km². The Great Barrier Reef Marine Park has 34.4 million ha, 344,000 km². Smaller coastal reserves of a few thousand hectares are described in square kilometres on posters and maps. A “convert ha to km²” calculation places each of them in a common scale.
Coffee, cocoa and tea plantations
Brazil grows coffee on about 2.2 million ha, 22,000 km², and Côte d'Ivoire has 4 million ha of cocoa, 40,000 km². India's tea gardens cover 630,000 ha, 6,300 km². Trade publications give plantation areas in hectares, while research on land use change tends to prefer square kilometres for regional comparisons.
The size of a district
A typical English county has between 100,000 and 400,000 ha, or 1,000 to 4,000 km². A German district is often 80,000 ha, 800 km². A French department averages 600,000 ha, 6,000 km². When you read a report about a regional programme, the unit matters little, but the conversion lets you judge whether the project is large or small compared to the area it serves.
Writing the unit with every number
In a report that uses both units, state hectares or square kilometres right after each figure and avoid shortening to a bare number. Readers skim, and a table that lists 25,000 in one column and 250 in the next invites a misreading. A footnote that says one square kilometre is 100 hectares costs a line and prevents most mistakes. After a “convert ha to km²” calculation, label the result clearly, and keep the same unit through the whole table.
A mental scale for large areas
A hectare is about the size of a rugby ground, so 100 hectares, a square kilometre, is a hundred such grounds in a ten by ten grid. A million hectares, 10,000 km², is a square 100 kilometres on a side, roughly the area of Lebanon. These pictures give a feel for the numbers that no formula can offer, and they let you spot a wrong answer from a “convert ha to km²” calculation at a glance.
Airports
Dallas Fort Worth International Airport covers about 6,960 ha, 69.6 km². London Heathrow covers 1,227 ha, 12.3 km². Frankfurt airport occupies 2,300 ha, 23 km². Airport authorities use hectares for planning and square kilometres when they compare their size with cities, so a “convert ha to km²” calculation is routine in aviation journalism.
Forests and timber land
The forests of Finland cover about 22 million ha, 220,000 km², some 75 per cent of the country. Sweden has 28 million ha, 280,000 km², and Germany 11.4 million ha, 114,000 km². Forestry agencies publish in hectares; maps of boreal forests are in square kilometres.
Lakes and reservoirs
Lake Constance has an area of 53,600 ha, 536 km². Lake Geneva covers 58,200 ha, 582 km². The Aswan High Dam's Lake Nasser reaches 520,000 ha, 5,200 km². Surface area is the main fact about a lake, and encyclopaedias give it in square kilometres, while water authorities often use hectares.
Mining and quarries
Open pit mines are among the largest excavations on earth. The Bingham Canyon mine in Utah covers about 770 ha, 7.7 km². A large quarry may have 200 ha, 2 km². Permits list hectares disturbed, environmental reports often translate to square kilometres to put the figures in context.
Rice, wheat and other crops
Thailand plants about 10 million ha of rice, 100,000 km². The wheat area of India is about 31 million ha, 310,000 km². These figures are given in millions of hectares by agricultural ministries and in square kilometres by geographers who put them on maps.
Islands and small states
Malta has 31,600 ha, 316 km². Luxembourg has 258,600 ha, 2,586 km². Singapore has 72,800 ha, 728 km². The conversion lets you compare a small country with a large park or a fire, which is often the point of such statistics.
Nature reserves and national parks
The Serengeti National Park covers 1.47 million ha, 14,700 km². Yosemite has about 303,000 ha, 3,030 km². The Danube Delta Biosphere Reserve has 580,000 ha, 5,800 km². Conservation bodies publish reserves in hectares, while tourist guides use square kilometres.
More values for convert ha to km²
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- 0.1 ha = 0.001 km²
- 0.5 ha = 0.005 km²
- 3 ha = 0.03 km²
- 4 ha = 0.04 km²
- 7 ha = 0.07 km²
- 15 ha = 0.15 km²
- 20 ha = 0.2 km²
- 75 ha = 0.75 km²
- 200 ha = 2 km²
- 500 ha = 5 km²
- 2,000 ha = 20 km²
- 10,000 ha = 100 km²
Mistakes when you convert ha to km²
Dividing by 10
That is the linear shift. For area, divide by 100.
Multiplying instead of dividing
The square kilometre is bigger, so the number shrinks. If 500 ha became 50,000, you multiplied.
Confusing with square metres
A square kilometre is a million square metres, not 100. The 100 is only the number of hectares.
Quick answers
How many hectares in a square kilometre?
100.
How do I convert ha to km²?
Divide by 100.
What is 2,500 ha in km²?
25 km².
How do I go back from km² to ha?
Multiply by 100.
Does my number leave my device?
No. The calculation runs in your browser.
Related pages and a last word
If you work with land and area, these conversions are close at hand: Convert ha to acres, Convert ha to m², Convert m² to km², Convert mi² to km², Convert km² to mi², Convert km to mi, Convert mi to km, Convert °C to °F, Convert °F to °C. The reverse of this page is Convert km² to ha.
In short, to convert ha to km² divide by 100, remember that a hectare is 10,000 m² and a square kilometre a million, and keep the digits your source supports. Your number stays on your device: nothing is uploaded and no account is needed.