Centimeters to Millimeters Converter (cm to mm)
1 cm = 10 mm exactly. Convert centimeters to millimeters for technical drawings, 3D printing, foot length and Korean shoe sizes, with charts.
Millimeter (mm) = Centimeter (cm) × 10
Centimeter (cm): The centimetre is one hundredth of a metre (0.01 m). It is used for everyday measurements such as body height, clothing and paper sizes, and one inch is exactly 2.54 cm.
Millimeter (mm): The millimetre is one thousandth of a metre (0.001 m). There are 10 millimetres in a centimetre, and exactly 25.4 millimetres in an international inch.
| Centimeter (cm) | Millimeter (mm) |
|---|---|
| 1 | 10 |
| 5 | 50 |
| 10 | 100 |
| 25 | 250 |
| 50 | 500 |
| 100 | 1000 |
Centimeters are the everyday metric unit, but drawings, CAD and 3D-printing software, machine parts and some sizing systems work in millimeters. Multiplying by 10 is all it takes, because the prefix milli- means one thousandth of a meter and centi- one hundredth. Screws and drill bits are labeled in millimeters too, so a 0.6 cm hole calls for a 6 mm bit.
Shoe sizing is a common case. Korea uses foot length in millimeters as its shoe size and Japan uses centimeters, so a foot measured at 26.5 cm takes size 265 in Korea. The shoe size converter compares those with US, UK and EU sizes.
How to use this tool
- Type a value in the Centimeter box to see it in millimeters, or type in the Millimeter box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Length converter.
Formula
Millimeter (mm) = Centimeter (cm) × 10
Centimeter (cm) = Millimeter (mm) × 0.1
Both factors come from exact definitions: 1 millimeter = 0.1 centimeters and 1 centimeter = 10 millimeters (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
26.5 cm × 10 = 265 mm
450 mm × 0.1 = 45 cm
Centimeter to Millimeter chart
Common values from centimeters to millimeters, rounded to four decimal places.
| Centimeter (cm) | Millimeter (mm) |
|---|---|
| 0.1 | 1 |
| 0.2 | 2 |
| 0.3 | 3 |
| 0.5 | 5 |
| 0.8 | 8 |
| 1 | 10 |
| 1.2 | 12 |
| 1.8 | 18 |
| 2.2 | 22 |
| 3.5 | 35 |
| 4 | 40 |
| 6.5 | 65 |
| 10 | 100 |
| 14 | 140 |
| 22 | 220 |
| 23.5 | 235 |
| 24 | 240 |
| 25 | 250 |
| 26 | 260 |
| 27 | 270 |
| 28 | 280 |
| 30 | 300 |
| 55 | 550 |
| 60 | 600 |
| 90 | 900 |
Millimeter to Centimeter chart
The reverse direction for values people often look up.
| Millimeter (mm) | Centimeter (cm) |
|---|---|
| 3 | 0.3 |
| 6 | 0.6 |
| 10 | 1 |
| 16 | 1.6 |
| 22 | 2.2 |
| 40 | 4 |
| 65 | 6.5 |
| 100 | 10 |
| 150 | 15 |
| 230 | 23 |
| 250 | 25 |
| 280 | 28 |
| 600 | 60 |
| 2,000 | 200 |
Lengths measured in centimeters
| Item | Centimeter (cm) | Millimeter (mm) |
|---|---|---|
| School ruler, the common metric length | 30 | 300 |
| Kitchen base cabinet, standard European depth | 60 | 600 |
| Size 5 soccer ball, minimum circumference | 68 | 680 |
| Cabin bag, a common height limit | 55 | 550 |
| Basketball ring, minimum inside diameter (FIBA) | 45 | 450 |
| Table tennis net height | 15.25 | 152.5 |
| A4 paper, short side | 21 | 210 |
Quick mental estimate
Add a zero, or move the decimal point one place right: 26.5 cm → 265 mm and 3 cm → 30 mm. Nothing is approximated; the result has exactly the precision of the centimeter figure you start with.
Use the converter or the charts when the exact figure matters.
The two units
Centimeter (cm): The centimetre is one hundredth of a metre (0.01 m). It is used for everyday measurements such as body height, clothing and paper sizes, and one inch is exactly 2.54 cm.
Millimeter (mm): The millimetre is one thousandth of a metre (0.001 m). There are 10 millimetres in a centimetre, and exactly 25.4 millimetres in an international inch.
Frequently asked questions
How many millimeters are in 2.5 cm?
Exactly 25 mm. That is close to an inch, which is 25.4 mm, so 2.5 cm and 1 inch are often treated as the same size in casual use, although the gap adds up over longer lengths.
Why do technical drawings use mm instead of cm?
Millimeters give whole numbers for most part dimensions and avoid mixing two metric units on one sheet. Metric engineering drawings conventionally give every dimension in millimeters, so a dimension with no unit is read as mm.
How do I measure in mm with a cm ruler?
Count the small marks: each one is 1 mm, and ten of them fill one centimeter. A reading of 7 cm plus 4 small marks is 74 mm.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/centimeter-to-millimeter-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Centimeters to Millimeters Converter (cm to mm). https://kakao.mobile/tools/centimeter-to-millimeter-converter/
“Centimeters to Millimeters Converter (cm to mm).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/centimeter-to-millimeter-converter/.
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