Centimeters to Millimeters Converter
Convert centimeters to millimeters instantly. One centimeter equals exactly 10 millimeters. Type in either box to convert both ways, then use the chart, worked examples and everyday sizes below.
How to convert centimeters to millimeters
Worked example: convert 64 centimeters to millimeters. Using millimeters ← centimeters × 10, we get 64 × 10 = 640 mm. To check the result, convert back: 640 mm ÷ 10 = 64 cm.
Centimeters to millimeters chart
| Centimeters (cm) | Millimeters (mm) |
|---|---|
| 1 cm | 10 mm |
| 2 cm | 20 mm |
| 3 cm | 30 mm |
| 4 cm | 40 mm |
| 5 cm | 50 mm |
| 6 cm | 60 mm |
| 8 cm | 80 mm |
| 10 cm | 100 mm |
| 12 cm | 120 mm |
| 15 cm | 150 mm |
| 20 cm | 200 mm |
| 25 cm | 250 mm |
| 30 cm | 300 mm |
| 40 cm | 400 mm |
| 50 cm | 500 mm |
| 75 cm | 750 mm |
| 100 cm | 1,000 mm |
| 150 cm | 1,500 mm |
| 200 cm | 2,000 mm |
| 250 cm | 2,500 mm |
| 500 cm | 5,000 mm |
| 1,000 cm | 10,000 mm |
Millimeters to centimeters (reverse)
| Millimeters (mm) | Centimeters (cm) |
|---|---|
| 1 mm | 0.1 cm |
| 2 mm | 0.2 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1 cm |
| 20 mm | 2 cm |
| 50 mm | 5 cm |
| 100 mm | 10 cm |
| 250 mm | 25 cm |
| 500 mm | 50 cm |
| 1,000 mm | 100 cm |
About the centimeter and the millimeter
The centimeter (centimetre) is one hundredth of a meter, about the width of a fingertip. Outside the United States it is the standard unit for body height, clothing measurements, furniture and parcel sizes.
A millimeter (millimetre) is one thousandth of a meter and is the everyday unit for small parts: screw diameters, phone thickness, rainfall totals and camera sensor sizes. A credit card is 0.76 mm thick, which gives a feel for the scale.
One centimeter equals 10 millimeters, which makes the centimeter the longer unit of the two.
Everyday sizes in centimeters and millimeters
| Everyday example (approximate) | In centimeters | In millimeters |
|---|---|---|
| The thickness of a credit card | 0.076 cm | 0.76 mm |
| The long side of an A4 sheet of paper | 29.7 cm | 297 mm |
| A typical adult's height | 170 cm | 1,700 mm |
| A standard interior door | 203.2 cm | 2,032 mm |
| A double-decker bus length | 1,100 cm | 11,000 mm |
| An Olympic swimming pool | 5,000 cm | 50,000 mm |
Centimeters to millimeters FAQ
How many millimeters are in one centimeter?
One centimeter equals exactly 10 millimeters. In the other direction, one millimeter equals 0.1 centimeters.
How do I convert centimeters to millimeters without a calculator?
convert 64 centimeters to millimeters. Using millimeters ← centimeters × 10, we get 64 × 10 = 640 mm. To check the result, convert back: 640 mm ÷ 10 = 64 cm. For a quick estimate, round the factor to 10. Then 64 cm is about 640 mm, compared with the exact 640 mm (an error of 0%). That is close enough for planning, but use the calculator above when the number matters.
What is a typical adult's height in millimeters?
A typical adult's height is about 170 centimeters, which is 1,700 millimeters. Treat that as an approximate everyday figure rather than an official measurement.
Are the centimeters and millimeters the same in every country?
The centimeter is exactly 0.01 m. The millimeter is exactly 0.001 m in every country that uses the metric system.