Convert m² to km² square metres ↔ square kilometres Free Online Secure
Type a value in square metres 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 m² to km² (square metres ↔ square kilometres)
| m² | km² |
|---|---|
| 1 | 0.000001 |
| 2 | 0.000002 |
| 3 | 0.000003 |
| 5 | 0.000005 |
| 10 | 0.00001 |
| 20 | 0.00002 |
| 50 | 0.00005 |
| 100 | 0.0001 |
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 square metre in practice?
A square one metre on each side. A standard interior door is about 1.8 square metres, a single bed about 2 and a small bathroom around 4. Floor space, paint coverage and property prices are usually quoted per square metre, so a rough feel for the size helps you judge whether a listed figure is generous or tight.
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.
The footprint of a spaceport, a mine or a landfill, in square kilometres
Engineers measure the ground taken by big projects in square metres, adding up pads, roads, pits and buildings. For a report, a news story or an environmental statement, they present the total in square kilometres. To convert m² to km² you divide by 1,000,000, which means moving the decimal point six places to the left. So 570,000,000 m² is 570 km², and 8,900,000 m² is 8.9 km². This page divides as you type, and the text below shows how large human projects look when they are measured in square kilometres, from launch sites to artificial islands.
Below come the rule, some worked cases, a brief look at each unit, a side by side comparison, a tour of large projects and the slips to avoid. Everything is computed on your own device while you type.
How to convert m² to km²: divide by 1,000,000
The rule
A million square metres make a square kilometre, exactly. Divide by 1,000,000, or slide the decimal point six places left, and you convert m² to km². Two million becomes 2, 350,000 becomes 0.35, 12,400,000 becomes 12.4. In reverse, multiply by a million.
Worked examples
The Fresh Kills landfill on Staten Island covered 8,900,000 m², 8.9 km². The Bingham Canyon copper mine in Utah occupies about 7,700,000 m², 7.7 km². The Palm Jumeirah in Dubai has 5,600,000 m², 5.6 km². When the figure has fewer than six digits, the result is a small fraction: 45,000 m² is 0.045 km².
Why six places
A kilometre is 1,000 metres, so a square kilometre is 1,000 times 1,000, a million square metres. The factor is the square of a thousand. Dividing by 1,000 gives an answer a thousand times too large, a slip that occurs when you are in a hurry.
A quick check
The square kilometre is the big unit, so the number must shrink by six digits. If your “convert m² to km²” calculation produced a number only three digits shorter, you used the length factor.
The square metre
The base unit of area
The square metre is the SI unit of area, the area of a square one metre on a side. It is used for rooms, plots, buildings and in every technical calculation of surfaces, from a balcony of 6 m² to a mine pit of millions of square metres.
Where it appears
Engineering reports, land registers, environmental impact studies, compensation claims and academic papers.
The square kilometre
A square of a thousand metres
The square kilometre is the area of a square 1,000 metres on a side, 100 hectares, 0.386 square miles. It is the unit of countries, regions, big lakes, large infrastructure and protected areas. Population density is given in people per square kilometre.
Where it appears
Atlases, official statistics, environmental assessments, news stories and encyclopaedias.
Square metre and square kilometre compared
A square kilometre holds a million square metres. One suits buildings and plots, the other regions and big projects. Between them, the hectare, 10,000 m², often serves for sites of 10 to 1,000 hectares.
The conversion is a pure shift of the decimal point, with no rounding. The danger lies in the number of zeros: six, not three. A habit of writing numbers with thousands separators helps you count them correctly.
Where the conversion appears
Spaceports and launch sites
The Kennedy Space Center covers about 570 km², 570,000,000 m², much of it wildlife refuge. The Baikonur Cosmodrome covers 6,717 km², over six billion square metres. Guiana Space Centre in French Guiana occupies 960 km². Reports use square kilometres for the total and square metres for pads and buildings, so a “convert m² to km²” calculation links the two.
Military bases and test ranges
Fort Bragg in North Carolina covers 650 km², 650,000,000 m². The White Sands Missile Range in New Mexico spans 8,300 km², 8.3 billion square metres. Training areas are given in square kilometres in official fact sheets, while barracks, runways and ranges use square metres in the plans.
Landfills and mines
The Fresh Kills landfill spread over 8.9 km², 8,900,000 m². The Mir diamond mine in Siberia has a pit of about 1.1 km² and a depth of 525 metres. The Chuquicamata copper mine in Chile covers about 8 km². Environmental assessments give both the pit area and the surrounding site, usually in square kilometres.
Artificial islands
The Palm Jumeirah covers 5.6 km², 5,600,000 m². The Hong Kong International Airport island has 12.5 km², 12,500,000 m². The Kansai Airport island in Osaka Bay is 10.5 km². Coastal engineers calculate land reclaimed in square metres and report it in square kilometres to the public, so a “convert m² to km²” calculation sits in every project summary.
Wind and tidal energy zones
A tidal energy lease might cover 3 km², 3,000,000 m², and an offshore wind lease 300 km², 300,000,000 m². The turbines occupy less than 1 per cent of the lease. Regulators publish lease areas in square kilometres, while environmental impact statements calculate seabed disturbance in square metres.
Tailings ponds and industrial waste sites
A tailings pond of 5 km², 5,000,000 m², with a depth of 20 metres stores 100 million m³ of waste. Regulators measure surface in square metres, report in square kilometres, and calculate volume by multiplying the area by an average depth. A “convert m² to km²” calculation is the first step in every such calculation.
Wildlife reserves and migration routes
A wildlife corridor of 100 km by 10 km covers 1,000 km², 1,000,000,000 m². Conservationists plan corridors in square kilometres and measure crossings, such as an animal bridge of 50 by 10 metres, 500 m², in square metres. Both units appear in one project document.
A list to remember
A tenth of a square kilometre is 100,000 m², a quarter is 250,000, a half 500,000 and three quarters 750,000. With these anchors you can judge any figure at a glance, and the converter above provides the exact digits.
Spreadsheet use
Write square metres in column A and =A2/1000000 in column B. For the reverse, use =B2*1000000. Format with four decimals for small sites. A total at the bottom lets you compare the sum of sites with the figure for the whole area.
Rounding
The conversion is exact. Give as many digits as the source: 8,900,000 m² is 8.9 km². If the source says about 9 million, write about 9 km². Do not add digits that the data cannot support.
Teaching the idea
Mark a square of one metre on the floor and imagine a thousand of them in a row, a kilometre. Then a thousand rows, a million squares. Students understand that one square kilometre is a million square metres and why the factor has six zeros.
How to describe a site to the public
Journalists often add a comparison to the number: "4.8 square kilometres, roughly 670 football pitches". The comparison makes the figure easy to remember. A good rule is to give the figure in the largest unit that keeps the number between 1 and 1,000, then add one familiar object. A “convert m² to km²” calculation is the first step; a picture is the second.
A picture of a square kilometre
A square kilometre is a square whose sides take a brisk walker twelve minutes. It holds 140 football pitches, or about 25 Central Parks put side by side. If the number from a conversion does not fit such a picture, check the zeros.
Ancient monuments and temple complexes
The Great Pyramid of Giza has a base of 53,000 m², 0.053 km². The Forbidden City in Beijing covers 720,000 m², 0.72 km². The Alhambra in Granada covers about 142,000 m², 0.14 km², and Angkor Wat 1,626,000 m², 1.63 km². Guidebooks state these sites in square metres or hectares, while atlases of world heritage prefer square kilometres, so a “convert m² to km²” calculation appears in every comparison.
Roofs of a country
The roof area of a medium sized city of 20 km² is about 3 km², 3,000,000 m². In Germany, roofs add up to about 3,000 km², and solar panels on a fraction of them already provide a large share of renewable electricity. Energy analysts compute roof potential in square metres per building and present the total in square kilometres.
Railway yards and marshalling
The Bailey Yard in Nebraska, the largest rail yard in the world, covers about 11.5 km², 11,500,000 m². A typical European marshalling yard covers 1 to 3 km². Railway companies keep area in acres or square metres, and the press converts to square kilometres to give readers a sense of scale.
Greenhouse districts
The greenhouse district of Westland in the Netherlands has glasshouses on roughly 30 km² of land, 30,000,000 m². A single glasshouse company may cover 0.5 km², 500,000 m². Agricultural statistics give square metres of glass for firms and square kilometres for districts.
Shopping and entertainment districts
A large shopping and entertainment district of 1.2 km², 1,200,000 m², may include 300,000 m² of buildings and 400,000 m² of car parks. The ratio of buildings to total land, 25 per cent, tells an analyst about density. Developers speak of square kilometres when they describe a district and square metres when they describe floors.
Fire breaks and defensible space
A fire break of 30 metres around a 10 km perimeter covers 300,000 m², 0.3 km². A forest management plan that clears 5 km² of undergrowth removes 5,000,000 m² of fuel. Fire services describe breaks in metres of width and area in hectares or square kilometres, and a conversion is needed in budget estimates.
Three ways to state one area
A site of 2,470,000 m² can be written as 247 hectares, 2.47 km² or 610 acres. All three are correct, and each serves a reader: the hectare is for planners and farmers, the square kilometre for geographers and the press, the acre for English speaking buyers. If you publish a figure, give the unit your audience knows first, and put the other in brackets. A “convert m² to km²” calculation is the bridge between the first and the second.
When the number has many digits
Large figures in square metres are hard to read: 12,345,678 m². Group the digits in threes, move the decimal point six places to the left, and round sensibly: 12.35 km². Then keep the long figure in your records and use the short one in text. Errors rarely come from the division, they come from losing a group of three digits while copying.
A brief history of the unit
The kilometre came out of the French metric reform of the 1790s, and with it the square kilometre as a natural measure of territory. Before that, lands were reckoned in leagues, arpents and other local units that differed from province to province. The new decimal system made it possible to add the areas of regions without conversions, and modern statistics rest on that idea. When you divide by a million, you are using the simplicity that the reformers wanted.
Human beings on a patch of ground
If all eight billion people stood close together at five per square metre, they would fit on 1,600 km², 1,600,000,000 m², a square 40 kilometres on a side, about the size of London. The calculation is a favourite illustration, and it needs only a division by a million to turn square metres into square kilometres.
Road networks
A motorway of 100 km with a width of 35 metres takes up 3,500,000 m², 3.5 km². A country with 2,000 km of motorways uses 70 km². Transport planners add roads, verges and junctions, and give the total in square kilometres in the environmental statement, though design drawings use square metres.
Sports and race circuits
A Formula One circuit with its paddock may cover 1 km², 1,000,000 m², and a motor racing complex such as the Nürburgring 1.5 km². A large stadium district covers 0.2 km², 200,000 m². Developers present sites in square kilometres to show scale, while the facilities are listed in square metres.
Solar farms in deserts
The Bhadla Solar Park in India occupies about 57 km², 57,000,000 m². Noor Ouarzazate in Morocco covers about 30 km². The Tengger Desert Solar Park in China covers 43 km². Each is described in square kilometres in news articles and in square metres in the engineering documents for panels and trackers.
Large reservoirs and dam lakes
The reservoir of the Three Gorges Dam covers 1,084 km², and Lake Mead about 640 km². In square metres, these are 1.08 and 0.64 billion. Hydrologists use square metres for volume calculations and square kilometres for the lake area, so the conversion appears in every hydrological study. A “convert m² to km²” calculation puts the two together.
Cities and urban sprawl
Greater London's built up area is 1,738 km², 1.74 billion m². Paris, 2,845 km², Tokyo, 8,547 km². Urban geographers measure built up areas by counting buildings and roads in square metres, and publish them in square kilometres for comparison. Definitions vary, so the same city may have several figures.
Ports and container terminals
The port of Singapore covers about 20 km², 20,000,000 m², and Rotterdam 126 km². A single container terminal may cover 1 km², 1,000,000 m², holding 30,000 boxes at once. Port authorities report land in hectares and square kilometres, and terminal operators speak of square metres of yard.
More values for convert m² 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 m² = 0.0000001 km²
- 0.5 m² = 0.0000005 km²
- 3 m² = 0.000003 km²
- 4 m² = 0.000004 km²
- 7 m² = 0.000007 km²
- 15 m² = 0.000015 km²
- 20 m² = 0.00002 km²
- 75 m² = 0.000075 km²
- 200 m² = 0.0002 km²
- 500 m² = 0.0005 km²
- 2,000 m² = 0.002 km²
- 10,000 m² = 0.01 km²
Mistakes when you convert m² to km²
Dividing by 1,000
That is the length factor. For area, divide by 1,000,000.
Multiplying instead of dividing
The square kilometre is bigger, so the number shrinks. If 500,000 m² became 500,000,000,000, you multiplied.
Counting zeros wrongly
A million has six zeros. Count them twice before you publish a report.
Quick answers
How many square kilometres in a square metre?
0.000001.
How do I convert m² to km²?
Divide by 1,000,000.
What is 500,000 m² in km²?
0.5 km².
How many square metres in a square kilometre?
1,000,000.
Is my number sent anywhere?
No, it stays in your browser.
Related pages and a last word
If you work with land and area, these conversions are close at hand: Convert m² to yd², Convert m² to ha, Convert mi² to km², Convert ha to km², Convert km² to ha, 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 m².
To sum up: divide by a million to convert m² to km², count the zeros twice, and write the unit beside the result. The figure you enter is processed in the browser and never leaves your computer.