Convert Centimetre to Millimetre

1 centimetre = 10 millimetre (mm). For example, 10 centimetre = 100 millimetre and 100 centimetre = 1,000 millimetre. Type any value below to convert centimetre to millimetre both ways — it runs entirely in your browser.

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Quick answer: Centimetre to Millimetre

1 Centimetre = 10 Millimetre (cm → mm). To convert centimetre to millimetre, multiply by 10. To convert millimetre to centimetre, multiply by 0.1. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common centimetre-to-millimetre questions.

How to convert Centimetre to Millimetre

To convert centimetre to millimetre, multiply the number of centimetre by the conversion factor 10, because 1 cm = 10 mm. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 mm = 0.1 cm, so you divide by 10 (or multiply by 0.1) to turn millimetre back into centimetre.

mm = cm × 10  ·  cm = mm × 0.1

  1. Write down the value you want to convert, in centimetre.
  2. Multiply it by 10.
  3. The result is the same area/length/quantity expressed in millimetre.

Centimetre to Millimetre — worked examples

Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 centimetre is 50 millimetre because 5 cm × 10 = 50 mm.

CentimetreCalculationMillimetre
1 cm1 cm × 10 = 10 mm10 mm
2 cm2 cm × 10 = 20 mm20 mm
3 cm3 cm × 10 = 30 mm30 mm
5 cm5 cm × 10 = 50 mm50 mm
7 cm7 cm × 10 = 70 mm70 mm
10 cm10 cm × 10 = 100 mm100 mm
12 cm12 cm × 10 = 120 mm120 mm
15 cm15 cm × 10 = 150 mm150 mm
20 cm20 cm × 10 = 200 mm200 mm
25 cm25 cm × 10 = 250 mm250 mm
50 cm50 cm × 10 = 500 mm500 mm
100 cm100 cm × 10 = 1,000 mm1,000 mm

Common Centimetre to Millimetre conversions

These are the centimetre-to-millimetre values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:

  • 1 centimetre = 10 millimetre
  • 2 centimetre = 20 millimetre
  • 2.5 centimetre = 25 millimetre
  • 3 centimetre = 30 millimetre
  • 4 centimetre = 40 millimetre
  • 5 centimetre = 50 millimetre
  • 6 centimetre = 60 millimetre
  • 7 centimetre = 70 millimetre
  • 8 centimetre = 80 millimetre
  • 9 centimetre = 90 millimetre
  • 10 centimetre = 100 millimetre
  • 12 centimetre = 120 millimetre
  • 15 centimetre = 150 millimetre
  • 20 centimetre = 200 millimetre
  • 25 centimetre = 250 millimetre
  • 30 centimetre = 300 millimetre
  • 50 centimetre = 500 millimetre
  • 75 centimetre = 750 millimetre
  • 100 centimetre = 1,000 millimetre
  • 200 centimetre = 2,000 millimetre
  • 500 centimetre = 5,000 millimetre
  • 1000 centimetre = 10,000 millimetre

Centimetre to Millimetre conversion chart (both directions)

The chart below converts centimetre to millimetre and millimetre to centimetre side by side, so it works whichever way you need. 1 centimetre = 10 millimetre, and 1 millimetre = 0.1 centimetre.

Centimetre → Millimetre Millimetre → Centimetre
0.25 cm = 2.5 mm 0.25 mm = 0.025 cm
0.5 cm = 5 mm 0.5 mm = 0.05 cm
1 cm = 10 mm 1 mm = 0.1 cm
2 cm = 20 mm 2 mm = 0.2 cm
3 cm = 30 mm 3 mm = 0.3 cm
4 cm = 40 mm 4 mm = 0.4 cm
5 cm = 50 mm 5 mm = 0.5 cm
6 cm = 60 mm 6 mm = 0.6 cm
7 cm = 70 mm 7 mm = 0.7 cm
8 cm = 80 mm 8 mm = 0.8 cm
9 cm = 90 mm 9 mm = 0.9 cm
10 cm = 100 mm 10 mm = 1 cm
12 cm = 120 mm 12 mm = 1.2 cm
15 cm = 150 mm 15 mm = 1.5 cm
20 cm = 200 mm 20 mm = 2 cm
25 cm = 250 mm 25 mm = 2.5 cm
30 cm = 300 mm 30 mm = 3 cm
40 cm = 400 mm 40 mm = 4 cm
50 cm = 500 mm 50 mm = 5 cm
75 cm = 750 mm 75 mm = 7.5 cm
100 cm = 1,000 mm 100 mm = 10 cm
150 cm = 1,500 mm 150 mm = 15 cm
200 cm = 2,000 mm 200 mm = 20 cm
250 cm = 2,500 mm 250 mm = 25 cm
500 cm = 5,000 mm 500 mm = 50 cm
1000 cm = 10,000 mm 1000 mm = 100 cm

Centimetre vs Millimetre: which is bigger?

1 cm1 mm
Relative size of 1 Centimetre (cm) and 1 Millimetre (mm).

A centimetre is the larger unit: one centimetre equals 10 millimetres. Put another way, you need 10 millimetres to make a single centimetre.

What is a Centimetre? History, origin and usage

The centimetre is one-hundredth of a metre, from the Latin centum, 'hundred'. It became prominent as the base length of the centimetre-gram-second (CGS) system used by many 19th- and early-20th-century physicists.

The centimetre is the everyday metric unit for small measurements such as human height, clothing sizes, paper and rulers across most of the world. It sits conveniently between the millimetre and the metre.

For decades scientists worked in the centimetre-gram-second system before the metre-kilogram-second system prevailed. A standard school ruler is typically 30 cm long.

What is a Millimetre? History, origin and usage

The millimetre is one-thousandth of a metre, taking its prefix from the Latin mille, 'thousand'. Like the other metric submultiples it dates to the French metric reform of the 1790s.

The millimetre is the workhorse of engineering drawings, machining and manufacturing, where tolerances are specified in millimetres or fractions of them. It is also the standard unit for rainfall and snowfall depth in meteorology.

Rainfall reported in 'millimetres' is the depth water would reach on a flat surface, so one millimetre of rain equals one litre per square metre. The smallest markings on most metric rulers are millimetres.

Convert 1 Centimetre to other units

It can help to see a centimetre next to the other units it is commonly compared with. One centimetre (cm) is equal to:

1 Centimetre equalsUnit
0.00001 kmKilometre
0.01 mMetre
0.1 dmDecimetre
10 mmMillimetre
10,000 µmMicrometre
0.000006213712 miMile
0.01093613 ydYard
0.0328084 ftFoot
0.3937008 inInch
0.000005399568 nmiNautical Mile
0.0000497097 furFurlong
0.000497097 chChain
0.0497097 liLink
0.001988388 rdRod
0.001988388 polePole
0.005468066 ftmFathom
0.0984252 handHand
0.04374453 spanSpan
0.08748906 fingerFinger
0.02187227 cubitCubit
0.00164042 ropeRope
0.0055 kenKen
0.000002071237 leaLeague
28.34646 ptPoint
6.6846e-14 AUAstronomical Unit
1.057e-18 lyLight-year
0.001 damDecametre
0.0001 hmHectometre
0.000001799856 nlNautical League

Convert 1 Millimetre to other units

One millimetre (mm) is equal to:

1 Millimetre equalsUnit
0.000001 kmKilometre
0.001 mMetre
0.01 dmDecimetre
0.1 cmCentimetre
1,000 µmMicrometre
6.2137e-7 miMile
0.001093613 ydYard
0.00328084 ftFoot
0.03937008 inInch
5.3996e-7 nmiNautical Mile
0.00000497097 furFurlong
0.0000497097 chChain
0.00497097 liLink
0.0001988388 rdRod
0.0001988388 polePole
0.0005468066 ftmFathom
0.00984252 handHand
0.004374453 spanSpan
0.008748906 fingerFinger
0.002187227 cubitCubit
0.000164042 ropeRope
0.00055 kenKen
2.0712e-7 leaLeague
2.834646 ptPoint
6.6846e-15 AUAstronomical Unit
1.057e-19 lyLight-year
0.0001 damDecametre
0.00001 hmHectometre
1.7999e-7 nlNautical League

Tips for converting Centimetre to Millimetre

  • To go from centimetre to millimetre, multiply by 10; to go back, divide by 10 (or multiply by 0.1).
  • For a quick mental estimate, remember that 1 centimetre ≈ 10 millimetre, so 10 centimetre ≈ 100 millimetre.
  • The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
  • Both fields update live as you type — change either side to convert in that direction.

How to use this Centimetre to Millimetre converter

Type a number into the Centimetre field and the equivalent in Millimetre appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Millimetre field to convert the other way (millimetre to centimetre). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.

Accuracy and method

Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 cm = 10 mm), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for centimetre-to-millimetre conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.

The metric units (km, m, cm, mm, µm) are exact by definition, and the imperial units (mile, yard, foot, inch, nautical mile) use their exact international values. Traditional units (hand, span, finger, cubit, rod/pole, link, rope, ken, league) are given at their commonly accepted standard sizes — historical local values sometimes differed, so confirm against a primary source before relying on them for legal or historical work.

Frequently asked questions

How many millimetre are in 1 centimetre?
1 centimetre = 10 millimetre (mm). To convert any number of centimetre to millimetre, multiply by 10.
How do I convert centimetre to millimetre?
Multiply the number of centimetre by 10. For example, 10 centimetre = 10 × 10 = 100 millimetre, and 25 centimetre = 250 millimetre.
How many centimetre are in 1 millimetre?
1 millimetre = 0.1 centimetre. So to convert millimetre back to centimetre, multiply by 0.1.
What is the formula to convert centimetre to millimetre?
millimetre = centimetre × 10. The reverse formula is centimetre = millimetre × 0.1.
How much is 100 centimetre in millimetre?
100 centimetre = 1,000 millimetre. (And 1000 centimetre = 10,000 millimetre.)
Which is bigger, a centimetre or a millimetre?
A centimetre is larger: 1 centimetre = 10 millimetre.
Is this centimetre to millimetre converter accurate?
Yes — every value is computed from the exact 10 mm per cm factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
Can I convert millimetre to centimetre too?
Yes. The converter works both ways — enter a value in either field. 1 millimetre = 0.1 centimetre.

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