Convert centimeters to millimeters

1 cm=10mm

Use the converter below to change any centimeters value into millimeters instantly — with formula, conversion table, and real-world examples.

You have

Equals

Conversion formula

Forward

millimeters = centimeters × 10

Reverse

centimeters = millimeters × 0.1

Example: 10 cm × 10 = 100 mm.

About both units

From

Centimeter

The centimeter equals one hundredth of a meter and is the everyday metric unit for body measurements, clothing sizes and furniture. European clothing tags, height on ID documents and household rulers are all marked in cm. An A4 sheet is 21 × 29.7 cm.

Real-world: An average adult is 160–185 cm tall. An A4 sheet is 21 × 29.7 cm. A standard passport photo is 3.5 × 4.5 cm.

Read full centimeter reference →

Millimeter

The millimeter equals one thousandth of a meter and is essential in precision engineering, manufacturing and rainfall measurement. A 10-millimetre rainfall is a moderate shower; over 50 mm in a day is classified as heavy. Machined parts, screws and PCB dimensions are all given in mm.

Real-world: A 2 euro coin is 25.75 mm across and 2.2 mm thick. Rainfall of 50 mm in 24 h is a red-warning event in most of Europe.

Read full millimeter reference →

Centimeter to Millimeter conversion table

Common centimeters to millimeters values for quick reference.

Centimeter (cm)	Millimeter (mm)
1 cm	10 mm
5 cm	50 mm
10 cm	100 mm
25 cm	250 mm
50 cm	500 mm
100 cm	1,000 mm
250 cm	2,500 mm
500 cm	5,000 mm
1,000 cm	10,000 mm
5,000 cm	50,000 mm

Tips & common mistakes

Quick tips

1 cm ≈ 0.394 inches — divide cm by 2.54 for a precise inch conversion.
Your little finger is about 1 cm wide at the nail — useful when no ruler is nearby.
100 cm = 1 metre exactly. Always convert to metres for architectural plans.

Avoid these

Confusing linear cm with square cm. 21 cm of ribbon is not the same as 21 cm² of fabric.
Using 2.5 instead of 2.54 for inch conversion — the 1.6% error grows on long measurements.
Reading a clothing size label as cm when it is actually an EU size code (e.g. size 42 ≠ 42 cm).

Frequently asked questions

How many millimeters in a centimeter?

One centimeter equals 10 millimeters.

How do I convert centimeters to millimeters?

Multiply the centimeter value by 10 to get the equivalent in millimeters.

What is 100 centimeters in millimeters?

100 centimeters equals 1,000 millimeters.

Is a centimeter bigger than a millimeter?

Yes. 1 centimeter equals 10 millimeters, so one centimeter is larger.

How to convert centimeters to millimeters without a calculator?

Multiply by 10 for a quick estimate; use a calculator for precise results.

Related length conversions

📊 See full comparison matrix →

Conversions in other categories

WeightKilogram → Pound TemperatureCelsius → Fahrenheit VolumeLiter → US Gallon AreaSquare Meter → Square Foot SpeedKilometer per Hour → Mile per Hour EnergyKilojoule → Kilocalorie PressureBar → Pound per Square Inch PowerKilowatt → Mechanical Horsepower