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Millimetres to centimetres

Multiply millimetres by 0.1 to get centimetres.

1 mm = 0.1 cmBIPM SI
mm
2.5cm

25 mm = 2.5 cm

How to convert millimetres to centimetres

The centimetre is one hundredth of a metre (10⁻² m). The millimetre is one thousandth of a metre (10⁻³ m).

Worked example — 25 mm: 25 × 0.1 = 2.5 cm.

Millimetres to centimetres table

Common conversions. The reverse table is on centimetres to millimetres.
MillimetresCentimetres
1 mm0.1 cm
5 mm0.5 cm
10 mm1 cm
20 mm2 cm
25 mm2.5 cm
50 mm5 cm
100 mm10 cm
250 mm25 cm
500 mm50 cm

Reverse and related

About millimetres and centimetres

Millimetre (mm)

1 mm = 0.1 cm

Definition. One thousandth of a metre (10⁻³ m)

History and origin

The millimetre is one thousandth of a metre, defined with the rest of the decimal metric system in the 1790s. Its small size suits precise work.

Current use

Millimetres are used for rainfall, engineering tolerances, and the sizes of screws, hardware and printed parts.

Source: BIPM, The International System of Units (SI), 9th ed. (2019)

Centimetre (cm)

1 cm = 10 mm

Definition. One hundredth of a metre (10⁻² m)

History and origin

The centimetre is one hundredth of a metre, part of the decimal metric system introduced in France in the 1790s. It was the base length of the older centimetre-gram-second system before the metre-kilogram-second system prevailed.

Current use

Centimetres are the everyday metric unit for body height, paper and screen sizes, and clothing measurements.

Source: BIPM, The International System of Units (SI), 9th ed. (2019)

Where people use this

Millimetres: rainfall, engineering tolerances, screws and hardware. Centimetres: height, paper and screen sizes, clothing measurements. 10 mm is exactly 1 cm.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 cm = 10 mm, so 1 mm = 1 ÷ 10 = 0.1 cm.

Every value is carried to full double precision; the display is rounded.

Both units are defined in BIPM, The International System of Units (SI), 9th ed. (2019).

Questions people ask

How many cm is 10 mm?

10 mm is exactly 1 cm.

How many mm make a cm?

It takes 10 millimetres to make one centimetre.

What is 25 mm in cm?

25 mm is 2.5 cm.

All millimetre conversions