Convert centimetres to millimetres instantly using the exact metric relationship 1 cm = 10 mm. You can also reverse the conversion, convert metres to millimetres, or convert inches to millimetres. The result stays hidden until you press Convert Length, and every numeric field uses a faint 0 placeholder only — the zero is not a real entered value.
The faint 0 inside every numeric field is only a placeholder. Type your number directly — entering 5 gives 5, not 05.
Your result appears after you press Convert Length.
One centimetre is divided into exactly ten millimetres. Moving from centimetres to millimetres therefore multiplies the numerical value by 10.
Convert one metric length into millimetres while also showing centimetres, metres and inches for quick comparison.
Enter or compare the original centimetre value.
See the exact result after multiplying by 10.
Compare the same length in metres.
Compare the metric length with international inches.
One centimetre always equals exactly ten millimetres.
Save the conversion and selected method for reference.
Centimetres and millimetres are both metric units of length. One centimetre contains exactly ten millimetres. That makes the conversion especially simple: multiply the centimetre value by 10.
Millimetres = Centimetres × 10For example, 5 cm × 10 = 50 mm. A decimal value works the same way: 12.5 cm × 10 = 125 mm.
The metric system is organised around powers of ten. The prefix centi means one hundredth, while milli means one thousandth. A centimetre is 0.01 metre and a millimetre is 0.001 metre. Dividing 0.01 by 0.001 gives exactly 10, so one centimetre equals ten millimetres.
| Centimetres | Millimetres | Metres |
|---|---|---|
| 0.1 cm | 1 mm | 0.001 m |
| 0.5 cm | 5 mm | 0.005 m |
| 1 cm | 10 mm | 0.01 m |
| 2.5 cm | 25 mm | 0.025 m |
| 5 cm | 50 mm | 0.05 m |
| 10 cm | 100 mm | 0.10 m |
| 25 cm | 250 mm | 0.25 m |
| 50 cm | 500 mm | 0.50 m |
| 100 cm | 1,000 mm | 1 m |
The reverse conversion divides millimetres by 10. For example, 85 mm ÷ 10 = 8.5 cm. Use the Reverse Convert option when the starting measurement is in millimetres.
Centimetres = Millimetres ÷ 10One metre contains exactly 1,000 millimetres. The Metres To Millimetres option multiplies metres by 1,000. For example, 2.4 m equals 2,400 mm.
The international inch is defined exactly as 25.4 millimetres. The Inches To Millimetres option multiplies inches by 25.4. This can be useful when construction drawings, hardware sizes or product specifications mix imperial and metric measurements.
Millimetres = Inches × 25.4Decimal centimetres are converted in exactly the same way as whole centimetres. A value such as 2.75 cm becomes 27.5 mm. The converter lets you select the number of decimal places displayed without changing the underlying calculation.
Centimetres may appear in general dimensions, furniture measurements or product sizes, while millimetres are often preferred in detailed construction drawings, fabrication, concrete thickness, reinforcement dimensions and precise component specifications.
3 cm equals 30 mm, 7.5 cm equals 75 mm, 12 cm equals 120 mm, 20 cm equals 200 mm and 45.6 cm equals 456 mm. Moving the decimal point one place to the right gives the same result as multiplying by 10.
Millimetres provide a smaller unit than centimetres, making it easier to state fine dimensions without fractions. A 2.35 cm thickness, for example, can be written as 23.5 mm. Many technical drawings use millimetres because this keeps dimensions consistent and compact.
This converter handles linear length only. Square centimetres to square millimetres use a factor of 100 because both dimensions are squared. Cubic centimetres to cubic millimetres use a factor of 1,000 because three dimensions are cubed.
Continue with the Millimetres To Centimetres Converter, Metres To Millimetres Converter, Inches To Millimetres Converter and Centimetres To Metres Converter.
Metric length units scale by powers of ten, which makes conversions predictable and exact.
Exact centimetre-to-millimetre relationship.
Ten centimetres equal one hundred millimetres.
One hundred centimetres make one metre.
One metre contains one thousand millimetres.
Answers about the exact ×10 conversion, reverse conversion, decimals, metres and inches.
There are exactly 10 millimetres in one centimetre.
Multiply centimetres by 10.
The 0 is only a placeholder, not an entered value. Typing 5 gives 5 rather than 05.
5 centimetres equal 50 millimetres.
12.5 centimetres equal 125 millimetres.
Yes. Use Reverse Convert, which divides millimetres by 10.
Yes. One metre equals exactly 1,000 millimetres.
Yes. One international inch equals exactly 25.4 millimetres.
Yes. One centimetre equals exactly 10 millimetres.
Yes. Centimetres use cm and millimetres use mm.
Yes. Values such as 2.75 cm convert directly to 27.5 mm.
Yes. The PDF includes the input, method and converted values.
Authoritative resources for SI units and metric measurement.
International reference for SI units, prefixes and definitions.
View SI BrochureU.S. National Institute of Standards and Technology metric and SI resources.
Visit NIST Metric ResourcesGuide for the use of the International System of Units.
View NIST SP 811Reference for metric prefixes including centi and milli.
View SI Prefixes