Convert m to cm metres ↔ centimetres Free Online Secure
Type a value in metres and read it in centimetres 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 m to cm (metres ↔ centimetres)
| m | cm |
|---|---|
| 1 | 100 |
| 2 | 200 |
| 3 | 300 |
| 5 | 500 |
| 10 | 1000 |
| 20 | 2000 |
| 50 | 5000 |
| 100 | 10000 |
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
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.
Where is the centimetre used in everyday life?
For anything a person measures against their own body: height, clothing sizes, the length of a sleeve, the width of a shelf, the dimensions of a parcel. A centimetre is roughly the width of a fingernail, which makes it easy to picture. It is large enough to avoid long strings of digits and small enough that you rarely need a decimal.
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 hundred centimetres to the metre: how to convert m to cm
Walk into any furniture shop and you will find two kinds of numbers. The room plan on the wall is drawn in metres, while the tag on the wardrobe gives centimetres. A tailor's tape, a shelf bracket, a child's height chart and a mattress label are all in centimetres, whereas the length of a corridor, the height of a ceiling and the width of a garden are quoted in metres. Moving between the two is one of the most common conversions in daily life, and to do it you convert m to cm. This page performs the calculation as you type.
The rule could hardly be simpler: a metre has exactly one hundred centimetres, so you multiply by 100, which moves the decimal point two places to the right. Yet people make mistakes with it, most often by moving the point the wrong way or by dropping a zero. The sections below set out the rule with examples, introduce both units, compare them, show where the conversion appears in practice and list the pitfalls to avoid.
How to convert m to cm: multiply by 100
The rule
One metre equals 100 centimetres. To convert m to cm, multiply the number of metres by 100 or shift the decimal point two places to the right. 1 m is 100 cm, 2.5 m is 250 cm, 0.75 m is 75 cm, 12 m is 1,200 cm and 0.045 m is 4.5 cm. Going the other way, divide by 100.
Worked examples
A doorway of 0.9 m is 90 cm wide. A ceiling 2.4 m high is 240 cm. A garden fence of 15.5 m is 1,550 cm. A baby of 0.52 m is 52 cm long. In each case the digits are the same and only the position of the decimal point changes.
The mental method
For a mental convert m to cm, think of a metre as a hundred centimetres and count in halves: 0.5 m is 50 cm, 0.25 m is 25 cm, 0.1 m is 10 cm. For any other value, take the digits after the decimal point as centimetres: 1.37 m is 1 m and 37 cm, which is 137 cm. Two decimals in metres are whole centimetres.
Three decimals
If the number of metres has three decimals, the third is a millimetre. 1.375 m is 137.5 cm. Keep the decimal in the answer, because dropping it would round to the nearest centimetre.
The metre
The base unit
The metre is the base unit of length in the International System. It was introduced in the 1790s as a ten-millionth of the distance from the pole to the equator, and since 1983 it has been defined as the distance light travels in vacuum in 1/299,792,458 of a second. Its symbol is m.
Everyday size
A metre is about the length of a long stride, the height of a kitchen worktop or the width of a wide doorway. Rooms, tracks, ropes and fabrics are commonly measured in metres.
The centimetre
A hundredth of a metre
The centimetre is one hundredth of a metre, about the width of a fingernail. The prefix centi comes from the Latin for a hundred. The unit has been the everyday small length of the metric world for two centuries and is used for height, clothing, furniture and printing.
Why it caught on
Centimetres are small enough to measure everyday objects without decimals and large enough to avoid long numbers. A person is 170 cm, not 1.7 m or 1,700 mm, which makes it the sweet spot for human-scale measurements.
Metre and centimetre compared
A metre is a hundred times longer than a centimetre. Numbers in centimetres are therefore two orders of magnitude larger than the same length in metres. Use metres for rooms and distances, centimetres for objects you can hold or wear.
In mixed contexts, such as a furniture plan, decide which unit you will use and stay with it. A drawing that shows a wall as 4.2 m and a cupboard as 60 cm invites confusion in the head. Put both in centimetres, 420 and 60, and the sum is simpler.
Where you will need it
Furniture and rooms
A sofa of 2.2 m fits against a wall of 3.5 m, leaving 1.3 m, which is 130 cm. Shops list a coffee table as 110 by 60 cm, so you need the room in centimetres to see how much space remains. A hallway of 1.1 m is 110 cm wide, and a wardrobe with doors that open 55 cm leaves 55 cm for walking.
Sewing and tailoring
Fabric is sold in metres, patterns are cut in centimetres. A dress that needs 2.75 m of cloth needs 275 cm. A pattern piece of 0.62 m is 62 cm. Seam allowances of 1.5 cm are small, but over a garment of 8 m of seams they add up to 12 cm of fabric.
Height and growth
Doctors record a child's height in centimetres, while parents mark the wall in metres. A boy of 1.28 m measures 128 cm and a girl of 1.05 m measures 105 cm. Growth of 6 cm per year is 0.06 m, which looks tiny but accumulates.
Sport
High jumpers clear 2.35 m, which is 235 cm. A long jump of 8.95 m is 895 cm. Records are quoted in metres and centimetres: 8.95 m is also 8 m 95 cm. Competitors speak the latter way.
Architecture and drawings
Scale drawings
Architectural plans use scales such as 1:50, where 1 cm on paper is 50 cm, half a metre, in reality. A wall of 4.6 m is 9.2 cm on the plan. Surveyors work in metres and architects often in centimetres, so the same line may appear as 4.60 and 460.
Tolerances
A joiner who is told that a window opening is 1.200 m wide with plus or minus 5 mm needs to translate it into 120 cm plus or minus 0.5 cm. A table of conversions near the bench prevents errors.
Everyday references
Things about a centimetre
The width of a fingernail, a small paper clip, a sugar cube. About 2.5 cm is the width of a thumb. A pencil is about 19 cm. Knowing references lets you check estimates.
Things about a metre
A baseball bat, a guitar, a doorknob to the floor. A step of an adult is 0.75 m. Using references, you can check that a conversion produced a sensible number.
Larger numbers
When metres become many centimetres
A football pitch of 105 by 68 m is 10,500 by 6,800 cm. The numbers become unwieldy, which is why large spaces are described in metres. Convert to centimetres only when you need to compare with small objects, such as how many 30 cm tiles line one side of the pitch: 350.
Thousands separators
Use separators to read large figures: 10,500 rather than 10500. In some locales a space or a point is used. Be consistent in a document.
A worked example: tiling a bathroom
Measuring and converting
A bathroom wall is 2.4 m wide and 2.1 m tall. Tiles are 30 by 20 cm. To plan, run the “convert m to cm” calculation step: the wall is 240 by 210 cm. Across the width, 240 divided by 30 gives 8 tiles. Up the height, 210 divided by 20 gives 10.5, so 11 rows with the last cut. That means 88 tiles, plus 10 per cent for breakage, about 97.
Why centimetres help
Tiles are sold in centimetres, so working in the same unit avoids confusion. The wall measurement in metres is correct, but dividing 2.4 by 0.3 is more error-prone than 240 by 30.
Choosing a bed, a desk and a bookcase
Fitting a child's room
A child's room is 3.2 m by 2.8 m. The bed is 90 by 200 cm, the desk 120 by 60 cm and the wardrobe 100 by 50 cm. To see whether everything fits, run the “convert m to cm” calculation step on the room: 320 by 280 cm. Put the bed along the long wall, leaving 120 cm; the desk along the short wall fits in 280 cm with 160 cm to spare; the wardrobe takes another 100 cm of the long wall. A free corridor of 60 cm remains, enough to pass.
Why drawing helps
Sketch the room on squared paper with one square for 10 cm. A bed is 9 by 20 squares, a desk 12 by 6. Cut paper shapes and push them around. This low-tech method often shows a layout that a list of numbers hides.
Using a tape measure well
Reading the marks
On a metric tape the long numbered marks are centimetres, the medium marks are 5 mm, and the short ones are millimetres. The numbers continue past 100 on most tapes, so a length of 1.37 m reads as 137. If your measurement is 2.45 m you will read 245 on the tape, and you do not even need to convert m to cm: the tape has done it for you.
Common errors
Holding the tape bent, forgetting the hook's thickness and measuring from the 10 cm mark without subtracting are classic mistakes. Check a measurement twice, once from each end, and the two readings should agree within a millimetre.
Science and laboratory work
Measuring small lengths
In school laboratories, lengths of a few centimetres are common: a pendulum of 0.5 m has a string of 50 cm, a spring stretched by 0.12 m is extended by 12 cm. Results in a table must use the same unit as the formula, which is usually metres for physics and centimetres for biology.
Converting for formulas
The period of a pendulum depends on length in metres. A length of 25 cm must be turned into 0.25 m before it goes into the formula. If you forget, the result is off by a factor of ten.
Photographs and prints
Print sizes
Photo prints are quoted in centimetres: 10 by 15, 13 by 18, 20 by 30. A poster of 0.5 by 0.7 m is 50 by 70 cm. A frame must be at least that size plus a mat of a few centimetres.
Resolution
An image 3,000 pixels wide printed at 300 dots per inch is 25.4 cm wide, 0.254 m. Converting to metres is rarely needed for photos, but can help when planning a large banner.
Spreadsheets and calculators
Formula
To convert m to cm for a list, put metres in column A and enter =A2*100 in column B. Format without decimals if you only need whole centimetres. To check, divide the result by 100. Filling down handles a long list.
Common traps
Some spreadsheets interpret a comma as a decimal point. In such a locale, type 1,25 for 1.25 m. A mismatch between the format and the locale can turn 1.25 into a date.
Rounding and precision
How many decimals
Two decimals in metres give whole centimetres, three give millimetres. A measurement made with a tape to the nearest centimetre should be written as 1.37 m, or 137 cm, never as 1.3700 m.
Mixed units
Writing 1 m 37 cm is clear, but sums are easier in centimetres. 1 m 37 cm plus 2 m 85 cm is 137 plus 285, which is 422 cm, or 4.22 m.
Teaching the idea
A metre stick
A metre stick marked in centimetres is the best teaching tool. Students count the marks, find that there are 100, and discover that each centimetre is a hundredth. They then measure objects in the room and write the result both ways.
The ladder of units
To convert m to cm on the ladder, draw it: kilometre, metre, centimetre, millimetre. Moving down multiplies, moving up divides. From metres to centimetres you step down once and multiply by 100.
Ropes, cables and tape
Cutting to length
Rope is sold by the metre but cut in centimetres. A job needing 6 pieces of 85 cm needs 510 cm, which is 5.1 m of rope. Buy 6 m to allow for waste and knots. Cable for a ceiling light of 1.8 m is 180 cm.
Packaging tape
A parcel of 60 by 40 by 30 cm needs tape around its length: 2 times 60 plus 2 times 40 is 200 cm, 2 m per wrap. Three wraps use 6 m. Roll length is given in metres, so convert before you buy.
Assembling flat-pack furniture
Reading the instructions
Flat-pack instructions give dimensions in centimetres, while room plans are in metres. A bookcase of 80 by 28 by 202 cm fits a wall of 2.4 m and a ceiling of 2.5 m. The diagram shows an alcove of 0.85 m, so you can see there is 5 cm of play.
Tolerances in assembly
Boards are cut with a tolerance of about 1 mm. Eight boards in a row could add 8 mm. Leave a gap of at least 1 cm in a built-in unit to avoid squeezing.
The history of the centimetre
From the French system
The centimetre appeared with the metric system and was soon used by artisans. The CGS system of units, centimetre-gram-second, was used in science from 1874 until the SI replaced it. Surface tension and magnetic quantities were originally expressed in CGS units.
Today
The centimetre is not an SI base unit, but it is accepted and widely used. Clothing and body measurements are universal in centimetres.
More values for convert m to cm
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 m = 10 cm
- 0.5 m = 50 cm
- 3 m = 300 cm
- 4 m = 400 cm
- 7 m = 700 cm
- 15 m = 1,500 cm
- 20 m = 2,000 cm
- 75 m = 7,500 cm
- 200 m = 20,000 cm
- 500 m = 50,000 cm
- 2,000 m = 200,000 cm
- 10,000 m = 1,000,000 cm
Mistakes when you convert m to cm
Moving the point the wrong way
Centimetres are smaller, so the number grows. If 2.5 m becomes 0.025, you moved left.
Moving three places
That gives millimetres. For centimetres, two places.
Forgetting the unit
A bare 150 could be centimetres or millimetres. Write cm after it.
Quick answers
How many centimetres in a metre?
One hundred.
How do I convert m to cm?
Multiply by 100.
What is 2.5 m in centimetres?
250 cm.
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 m to km, Convert m to yd, Convert in to cm, Convert dm to cm, Convert cm 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 cm to m.
In short, to convert m to cm multiply by a hundred, move the decimal point two 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.