Convert km to m kilometres ↔ metres Free Online Secure
Type a value in kilometres and read it in metres 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 km to m (kilometres ↔ metres)
| km | m |
|---|---|
| 1 | 1000 |
| 2 | 2000 |
| 3 | 3000 |
| 5 | 5000 |
| 10 | 10000 |
| 20 | 20000 |
| 50 | 50000 |
| 100 | 100000 |
Where these units come from
The metre was first defined in 1793 as a ten-millionth of the distance from the equator to the North Pole — a definition nobody could check without surveying a quarter of the planet. It has been redefined four times since, each time to something steadier: a platinum bar, then a prototype kept in Paris, then a wavelength of krypton light, and since 1983 the distance light travels in vacuum in 1/299,792,458 of a second. The inch stopped being a separate thing in 1959, when six countries agreed to define it as exactly 25.4 mm. That agreement is why every conversion on this page between a metric and an imperial length is exact rather than measured: both sides now descend from the same definition.
Where you meet them
Millimetres are the working unit of engineering drawings and of anything made in a workshop; centimetres belong to tailoring, furniture and school rulers; metres to rooms, fabric and running tracks. Feet and inches survive in aviation altitudes worldwide, in American and British construction, and in the diagonal of every screen you have ever bought. Nautical miles are not a quaint survival — one is a minute of latitude, which is why ships and aircraft still navigate in them.
Questions people ask
Which countries still measure road distances in miles?
The United States and the United Kingdom, where road signs show miles, together with a handful of smaller countries such as Liberia and Myanmar. Almost everywhere else road distances are in kilometres. One kilometre is 1000 metres and about 0.621 of a mile, so a distance in miles is about five-eighths of the same distance in kilometres.
How is the metre defined today?
As the distance light travels in a vacuum in 1/299,792,458 of a second. The definition has been in place since 1983 and ties the metre to the speed of light, which is itself fixed at exactly 299,792,458 metres per second. The old platinum bar in Paris no longer defines anything.
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.
A thousand steps at a time: how to convert km to m
The kilometre and the metre are the two units on which almost all everyday distance rests. A road sign gives the kilometres to the next town; a stadium plan, a swimming pool and a tailor's tape use metres. Learning to convert km to m is among the most frequent skills people need, and it is simple enough to do in the head once you see why. When a route is 7.5 km long and the map of the park shows only metres, you have to convert km to m, and this page does it the moment you type the number.
The relationship is exact: a kilometre is a thousand metres, so the conversion is a multiplication by 1,000, which moves the decimal point three places to the right. The sections that follow set out the rule with examples, trace where the two units come from, compare them, list the places where the conversion is needed and point out the slips to avoid. Short as the topic is, a few details are worth knowing, especially when decimals are involved.
How to convert km to m: multiply by 1,000
The rule
There are 1,000 metres in a kilometre. To convert km to m, multiply the number of kilometres by 1,000, or move the decimal point three places to the right. 1 km is 1,000 m, 5 km is 5,000 m, 0.5 km is 500 m and 2.75 km is 2,750 m. When the kilometre figure has fewer than three decimals, add zeros: 3.4 km is 3,400 m. To go the other way, divide by 1,000; the reverse operation is the mirror image.
Worked examples
A school run of 1.8 km is 1,800 m. A lake whose shore path measures 4.25 km has a path of 4,250 m. A marathon, 42.195 km, is 42,195 m. A short footbridge of 0.08 km is 80 m. Each case follows the same pattern: three places to the right.
Mental checks
If you are unsure how to convert km to m, think of a kilometre as a thousand large paces. Then 2 km are two thousand paces. A quick test of the answer is to count digits: a whole number of kilometres with n digits gives metres with n plus 3 digits. 12 km becomes 12,000 m, five digits for two.
Decimals in the answer
If the number of kilometres has more than three decimals, the answer in metres will have decimals too: 0.0125 km is 12.5 m. The extra digits are real millimetres, so keep them only if your measurement supports them.
The kilometre
Long distances
The kilometre is the unit of road and rail distance in nearly all the world. The prefix kilo comes from the Greek for a thousand, and the symbol is km. A kilometre is about twelve minutes on foot, three minutes by bicycle and a minute by car in town traffic.
Where it appears
Signposts, maps, car odometers, running apps, flight distances and the length of rivers are given in kilometres. In the United States and the United Kingdom road distances are still in miles, though sports there often use kilometres.
The metre
The base of the system
The metre is the base unit of length in the International System of Units. It was proposed in 1791 as one ten-millionth of the distance from the North Pole to the equator, and since 1983 it has been defined from the speed of light: the distance light travels in a vacuum in 1/299,792,458 of a second.
Everyday feel
A metre is about the length of a long stride, the height of a kitchen counter or the width of a doorway plus a hand. Rooms, running tracks, pools, ropes and cables are measured in metres.
Kilometre and metre compared
A kilometre is a thousand metres, so the same distance gives a number a thousand times bigger in metres than in kilometres. Choose the unit that keeps the number readable: 12 km is more natural than 12,000 m for a bike ride, but 80 m is more natural than 0.08 km for a footbridge.
In mixed texts, switch units where the size changes. A trail guide may say that the walk is 6 km long and climbs 250 m. It would be odd to write the climb as 0.25 km or the length as 6,000 m. Do this consciously: write both forms in one place only if you want to show a conversion.
Where you will need it
Athletics and running
A 10 km race is 10,000 m, and the track record for the distance is quoted in metres on the stadium board. A 5 km parkrun has 12.5 laps of a 400 m track. Runners who read a training plan in kilometres and a track in metres benefit from convert km to m for every session.
Cycling and hiking
A bike computer shows 32.4 km, while a segment on a map is listed as 800 m. To compare, convert the km figure to 32,400 m. A hiker who sees an altitude gain of 650 m on a trail of 11 km finds a gradient of about 5.9 per cent, calculated as 650 divided by 11,000.
Building and surveying
Roads, pipelines and cables are planned in kilometres but constructed in metres. A pipeline of 3.6 km needs 360 sections of 10 m. A surveyor staking out the line works at 20 m intervals, so 180 stakes. Converting once at the start prevents arithmetic errors later.
Speeds
To change a speed from km/h to m/s, divide by 3.6. This is the same factor, 1,000 m per km divided by 3,600 s per h. A car at 90 km/h moves at 25 m/s; a runner at 12 km/h at 3.33 m/s.
Timing a kilometre
Pace and speed
A runner who does a kilometre in five minutes runs at 12 km/h, which is 3.33 m/s, or 200 m per minute. Knowing the pace per kilometre and the speed in metres per second together lets you plan intervals on a 400 m track: 400 m at 3.33 m/s takes 120 seconds.
Walking
An easy walking speed of 5 km/h is 1.39 m/s, about 83 m per minute. A kilometre takes 12 minutes. A distance of 2,500 m, as written on a park signboard, is therefore 30 minutes at this speed.
Everyday references
Things that are a kilometre
Ten football pitches in a row, a long street, the length of a big airport terminal doubled. A tower of 828 m, Burj Khalifa, is about eight tenths of a kilometre.
Things that are a metre
A child of four years, a guitar, a baseball bat plus a hand. Use these references to judge whether an answer is plausible.
Related units to know
Other lengths in the family
One kilometre is 1,000 m, 100,000 cm, 1,000,000 mm, 0.6214 mi, 3,281 ft and 0.54 nautical miles. Each conversion can be done from the metre value on the page: multiply the metres by 100 for centimetres, by 1,000 for millimetres, divide by 1,609.34 for miles.
From metres to anything
Once you have the figure in metres, you can reach every other length unit. That makes the metre the central hub of any length calculation.
Planning a trip
Daily distances
A cycling holiday of 60 km a day for 5 days covers 300 km, 300,000 m. A walking route of 20 km a day takes 20,000 m of steps, about 26,000 steps. Counting in metres gives you a feel for how many steps are needed.
Fuel and travel time
A car using 6 litres per 100 km burns 0.06 litres per kilometre, 0.00006 per metre. The figures are small, which is why consumption is quoted per hundred kilometres. The conversion to metres rarely adds anything beyond curiosity.
A complete example: planning a charity walk
From the route to the checkpoints
An organiser plans a charity walk of 12.6 km with water stations every 2.1 km and a first-aid post at the 6.3 km mark. To place the volunteers on the ground, the committee must convert km to m for each point: 12.6 km is 12,600 m, a water stop every 2,100 m, first aid at 6,300 m. A marshal with a measuring wheel can then mark the exact spots. The route has six equal sections, each 2,100 m long, so six water stations including the finish.
Budget and supplies
If there are 800 walkers and each should have 0.5 litres of water per stop, the water needed is 400 litres per station. The distance in metres is also what a signwriter needs: a marker every 500 m means 25 markers on the 12,600 m route. All of these quantities come from one conversion done at the start.
Reading a map scale
From centimetres on paper to kilometres on the ground
On a 1:25,000 hiking map, 1 cm on the page is 25,000 cm on the ground, which is 250 m. A trail that measures 8 cm on the map is 2,000 m, or 2 km. The kilometre-to-metre conversion is the last step, after the scale has been applied. With a 1:50,000 map, 1 cm is 500 m, so a route of 12 cm is 6 km, 6,000 m.
Why scale matters
Maps for walkers use a large scale so that paths are visible, and maps for drivers a small one. When you convert km to m for a route you have drawn on a map, check the scale printed at the bottom; it is the one number that connects paper to land.
Rivers and borders
Long lines on the map
The Danube is about 2,850 km long, which is 2,850,000 m. The Rhine is 1,230 km, 1,230,000 m. Borders are measured in kilometres too: a frontier of 650 km is 650,000 m. These numbers show why long lines on maps are nearly always given in kilometres.
Why not metres?
Six or seven digits are hard to read and give an impression of exactness that the measurement does not have. The precision of a river length is a few kilometres, not a few metres.
Roads, rails and cables
Infrastructure numbers
A motorway lane of 100 km has 100,000 m of lane markings per line. A railway of 50 km uses about 100 km of rail, 100,000 m, since there are two rails. A power line of 20 km between towers every 300 m needs 67 towers.
Cost per metre
Tenders quote prices per metre. If a pipeline costs 450 euros per metre, one kilometre costs 450,000 euros. A route of 12.3 km costs 5.535 million. Converting the length once, then multiplying, avoids repeated errors.
Elevation and gradient
Combining vertical and horizontal
Elevations are given in metres, distances in kilometres. To find the gradient, put both in the same unit. A road that climbs 120 m over 3 km rises 120 m in 3,000 m, a gradient of 4 per cent. Many road signs show the percentage directly.
Cycling climbs
A mountain stage with a climb of 1,200 m over 14 km has an average slope of 8.6 per cent. Cyclists compare climbs in this way; the conversion to metres is the step that makes it possible.
Digital maps and GPS
Distances on a screen
Map apps show distances in metres below one kilometre and in kilometres above it. When the display changes from 950 m to 1.0 km, nothing special has happened; the app has switched units. If you copy a value from one screen to a spreadsheet, check which unit it was in.
Accuracy
Phone GPS is accurate to about 5 m in open areas. Thus a distance of 3.2 km is meaningful to the nearest 10 m at best, and quoting it as 3,214 m invents precision. Round to the unit that fits the measurement.
The history of the metre
A revolution in measurement
Before the French Revolution, Europe used a patchwork of local lengths. The metre was created to replace them with a universal standard based on the Earth. Surveyors measured the meridian from Dunkirk to Barcelona between 1792 and 1798 to fix it. The kilometre followed naturally as a thousand metres.
A modern definition
Since 1983 the metre has been defined from the speed of light. One kilometre is the distance light travels in about 3.34 microseconds. The definition makes the units independent of any physical object.
Spreadsheets and data
Formula
To convert km to m for a whole column, put kilometres in column A and enter =A2*1000 in column B. Format without decimals unless the source has decimals. To check, divide the result by 1000 and compare with the original. For large datasets, apply the formula to a whole column and fill down.
Avoiding mixed columns
Never keep metres and kilometres in the same column. If a source mixes them, add a unit column and convert the whole column to one unit before sorting or summing.
Rounding and significant figures
Keep what you know
A distance of 4.2 km has two significant figures; in metres, it is 4,200 m, but you should read it as 4.2 times 10 to the third. Writing 4,200.0 m would claim a precision of 0.1 m that the original lacks.
Scientific writing
Use scientific notation when it matters: 4.2e3 m. That shows two significant figures, no more.
Teaching the idea
Walking a measured kilometre
Have a class walk 100 m, time it and multiply by 10 to estimate the time for a kilometre. Pace it: about 1,300 steps. Then compute metres per step: 1,000 divided by 1,300 is 0.77 m. The exercise links distance, time and units.
The power-of-ten ladder
Draw the ladder from kilometre to metre to centimetre to millimetre, each step a factor of ten or one hundred. Moving down multiplies, moving up divides.
More values for convert km to m
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 km = 100 m
- 0.5 km = 500 m
- 3 km = 3,000 m
- 4 km = 4,000 m
- 7 km = 7,000 m
- 15 km = 15,000 m
- 20 km = 20,000 m
- 75 km = 75,000 m
- 200 km = 200,000 m
- 500 km = 500,000 m
- 2,000 km = 2,000,000 m
- 10,000 km = 10,000,000 m
Mistakes when you convert km to m
Moving the decimal the wrong way
Metres are the smaller unit, so the number grows. If 3.4 km becomes 0.0034, you moved left instead of right.
Moving two places
That gives hectometres. For metres, three places.
Mixing units
Add kilometres to kilometres, metres to metres, never one to the other. Convert first.
Quick answers
How many metres in a kilometre?
One thousand.
How do I convert km to m?
Multiply by 1,000.
What is 3.4 km in metres?
3,400 m.
Is the conversion exact?
Yes, exact.
Does my number leave my device?
No. The calculation runs in your browser.
Related pages and a last word
If you work with lengths, these conversions are close at hand: Convert km to dm, Convert km to mi, Convert nm to m, Convert ft to m, Convert m to mm, Convert °C to °F, Convert °F to °C, Convert L to gal, Convert gal to L. The reverse of this page is Convert m to km.
In short, to convert km to m multiply by a thousand, move the decimal point three places to the right and keep only the digits your measurement supports. Your number stays on your device: nothing is uploaded and no account is needed.