Skip to content
UnitCalculators.com

Metres to millimetres

Multiply metres by 1,000 to get millimetres.

1 m = 1,000 mmBIPM SI
m
2,000mm

2 m = 2,000 mm

How to convert metres to millimetres

The millimetre is one thousandth of a metre (10⁻³ m). The metre is the SI base unit of length, defined since 1983 by fixing the speed of light at exactly 299 792 458 m/s.

Worked example — 2 m: 2 × 1,000 = 2,000 mm.

Metres to millimetres table

Common conversions. The reverse table is on millimetres to metres.
MetresMillimetres
0.1 m100 mm
0.25 m250 mm
0.5 m500 mm
1 m1,000 mm
2 m2,000 mm
5 m5,000 mm
10 m10,000 mm
50 m50,000 mm
100 m100,000 mm

Reverse and related

About metres and millimetres

Metre (m)

1 m = 1,000 mm

Definition. The SI base unit of length, defined since 1983 by fixing the speed of light at exactly 299 792 458 m/s

History and origin

The metre was defined in 1793 as one ten-millionth of the distance from the equator to the North Pole, later realised as a platinum bar. Since 1983 it has been defined by fixing the speed of light at exactly 299 792 458 metres per second, tying it to a constant of nature rather than an object.

Current use

The metre is the base unit of length across the metric world, used for everything from building plans to sports fields; the United States is the main country that still measures everyday length in feet and inches.

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

Millimetre (mm)

1 mm = 0.001 m

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)

Where people use this

Metres: room and building dimensions, sports fields, fabric and rope. Millimetres: rainfall, engineering tolerances, screws and hardware. 1 m is exactly 1000 mm.

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 mm = 0.001 m, so 1 m = 1 ÷ 0.001 = 1,000 mm.

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 mm are in a metre?

One metre is exactly 1000 millimetres.

How many mm is 2 m?

2 metres is 2000 mm.

What is 0.5 m in mm?

Half a metre is 500 mm.

All metre conversions