Millimetres to Centimetres Converter

This converter changes a length in millimetres into centimetres, the everyday step you need when reading a ruler, a tape measure, a technical drawing or a set of building plans that mix metric units. Enter your value in the millimetres field and the result updates instantly, showing the equivalent in centimetres using the exact factor of 0.1, since one millimetre is defined as a tenth of a centimetre and one centimetre equals ten millimetres. Below the result you will also see quick reference conversions for both directions, so you can check the relationship without doing the sums yourself. A worked example shows the calculation step by step: multiplying 10 millimetres by 0.1 gives 1 centimetre, and the same formula, centimetres equals millimetres times 0.1, applies whatever number you enter. A quick-reference table further down lists common values from 1 millimetre through to 100 millimetres, handy for sewing, woodworking, model-making, school homework or any job where plans are marked in millimetres but you are more used to thinking in centimetres. Because the factor comes from the fixed international definitions of the metre and the inch, the underlying conversion is exact; the figure shown on screen is simply rounded for readability. Use this tool whenever you need a fast, reliable swap between the two units, without reaching for a calculator or working the maths out by hand.

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0.1 cm
1 mm =0.1 cm
1 cm =10 mm

The formula

Multiply millimetres by 0.1 to get centimetres. In symbols, cm = mm × 0.1. To go the other way, multiply centimetres by 10 to get millimetres.

Worked example

Convert 10 millimetres to centimetres: 10 × 0.1 = 1 centimetres.

Quick reference

MillimetresCentimetres
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

Frequently asked questions

How many centimetres are in one millimetre?

One millimetre equals 0.1 centimetres. Multiply the number of millimetres by 0.1 to convert.

What is the formula to convert millimetres to centimetres?

Millimetres times 0.1 equals centimetres. To reverse it, multiply centimetres by 10 to get millimetres.

Is the mm to cm conversion exact?

The factor comes from the standard definitions of the metre and the international inch (0.0254 m exactly), so the underlying conversion is exact. Displayed results are rounded for readability.

Who this converter is for

This converter is for students, tradespeople, travellers and anyone who needs to change millimetres into centimetres quickly and accurately.

What this converter assumes

  • You enter a length in millimetres.
  • The factor used is 0.1 centimetres per millimetre.
  • Results are rounded for display.

Sources

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