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MM to CM Converter

Convert millimeter to centimeter instantly. 1 mm = 0.1 cm, worked steps and a full reference table.

Formula
cm = mm × 0.1

How to use it

  • Type the value in millimeter — the result updates as you type.
  • Use Swap to flip the direction, or change either dropdown to convert between any two units.
  • Click the result to copy it. The URL updates too, so you can bookmark or share the exact conversion.

Examples

1 mm0.1 cm
5 mm0.5 cm
10 mm1 cm
100 mm10 cm

One millimeter equals 0.1 centimeters (cm). To convert millimeters to centimeters, multiply by 0.1; to go back the other way, multiply by 10 instead.

The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.

What millimeters and centimeters actually measure

Millimeter (mm) — A millimetre is a thousandth of a metre, and the smallest division on a normal ruler. Engineering drawings, timber and steel sizes, rainfall and screen bezels.

Centimeter (cm) — A centimetre is a hundredth of a metre. Body measurements, clothing sizes, paper and furniture dimensions across most of the world.

MM to CM conversion table

The most common values, worked out in advance. Anything not listed can be typed straight into the converter.

mmcm
1 mm0.1 cm
2 mm0.2 cm
5 mm0.5 cm
10 mm1 cm
25 mm2.5 cm
50 mm5 cm
100 mm10 cm

How to convert millimeters to centimeters by hand

Multiply the number of millimeters by 0.1.

For example, 25 mm × 0.1 = 2.5 cm.

Going the other way, divide by 0.1 — or multiply by 10, which is the same thing and easier to do in your head.

Everything runs in your browser

There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.

Questions people ask

How many cm are in 1 mm?

1 mm equals exactly 0.1 cm. Multiply any value in millimeter by 0.1 to get centimeter.

Is anything uploaded to a server?

No. The whole calculation happens in your browser. Nothing is sent anywhere, and the page keeps working offline once loaded.

Runs entirely in your browser. Nothing you type is uploaded, logged or shared.

Last updated 18 August 2026