How many millimeters are in 1 centimeter?

One centimeter contains exactly 10 millimeters. This is the defining 'centi to milli' metric relationship.

How do I convert cm to mm?

Multiply by 10 or move the decimal point one place right. For example, 3.5 cm = 35 mm.

When do I use mm instead of cm?

Engineering and manufacturing prefer millimeters because most part dimensions are whole numbers in mm. A 25 mm bolt is cleaner than 2.5 cm. Medicine also uses mm for small measurements like tumor sizes.

Centimeters to Millimeters (cm to mm) Converter

1 cm = 10 mm

1 Centimeter equals 10 Millimeters (1 cm = 10 mm). Convert Centimeters to Millimeters with formula, table, and examples.

One centimeter equals exactly 10 millimeters. This is the simplest and most frequently used metric conversion in everyday life. Moving from centimeters to millimeters just shifts the decimal one place right. Both units appear on every metric ruler.

How to Convert Centimeters to Millimeters

mm = cm × 10

Multiply the value in Centimeters by 10

Take your value in Centimeters
Multiply by 10
Read the result in Millimeters

Common Centimeters to Millimeters Conversions

Centimeters (cm)	Millimeters (mm)	Status
0.1 cm	1 mm
0.5 cm	5 mm
1 cm	10 mm
2 cm	20 mm
3 cm	30 mm
5 cm	50 mm
10 cm	100 mm
15 cm	150 mm
20 cm	200 mm
25 cm	250 mm
30 cm	300 mm
50 cm	500 mm
100 cm	1,000 mm
200 cm	2,000 mm
500 cm	5,000 mm
1,000 cm	10,000 mm

Good to Know About Centimeters to Millimeters Conversion

Every metric ruler has both cm and mm markings. Children learn centimeters first. Engineers learn to think in millimeters. The transition from cm-thinker to mm-thinker is one of the subtle signs of technical training.

Centimeters to Millimeters: What You Need to Know

A 30 cm ruler shows 300 mm. A credit card at 8.56 cm is 85.6 mm. A human hair at 0.0075 cm is 0.075 mm (75 micrometers). In engineering drawings, millimeters are standard because they avoid decimal points for common dimensions. A 2.5 cm bolt is simply a 25 mm bolt.

What is a Centimeter? cm

A metric unit of length equal to one hundredth of a meter. Commonly used for body height, clothing sizes, and everyday measurements.

Metric body height clothing furniture

Learn more about Centimeter →

What is a Millimeter? mm

A metric unit of length equal to one thousandth of a meter. Used in engineering, manufacturing, and precise measurements.

Metric engineering manufacturing rainfall

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Going the other way? Use our Millimeters to Centimeters converter.

Centimeters to Millimeters FAQ

One centimeter contains exactly 10 millimeters. This is the defining 'centi to milli' metric relationship.
Multiply by 10 or move the decimal point one place right. For example, 3.5 cm = 35 mm.
Engineering and manufacturing prefer millimeters because most part dimensions are whole numbers in mm. A 25 mm bolt is cleaner than 2.5 cm. Medicine also uses mm for small measurements like tumor sizes.

Non-Frequently Asked Questions About Centimeters to Millimeters

Questions nobody should ask - but someone did.

For the same reason you need both dollars and dimes. Centimeters give round numbers for everyday objects (a phone is 15 cm). Millimeters give round numbers for precision work (a screw is 8 mm). Using the wrong one is like paying for coffee in pennies.