Length

m to mm conversion

Convert metre (m) to millimetre (mm). Length units span pipe diameters (mm, inch), plant dimensions (m, ft), and roughness (µm) — mixing metric and imperial is routine.

1 m = 1000 mm

Formula

To convert metre to millimetre, multiply the m value by 1000. To go the other way, divide by 1000 (or multiply by 0.001).

m to mm conversion table

m	mm
1	1000
2	2000
5	5000
10	10000
25	25000
50	50000
100	100000
250	250000
500	500000
1000	1000000

Used in practice

Pipe sizes are labelled in inches (NPS) but calculated in mm; equipment layouts mix metres and feet.

Velocity scales with the inverse square of diameter, so a small length error compounds quickly in flow calculations.

Worked example. A length of 0.1 m is 100 mm.

Frequently asked questions

How do you convert metre to millimetre?

Multiply the value in m by 1000 to get mm. For example, 10 m = 10000 mm.

What is 1 m in mm?

1 m equals 1000 mm.

Where is this conversion used?