Length

mil to m conversion

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

1 mil = 2.54e-5 m

Formula

To convert thousandth of an inch to metre, multiply the mil value by 2.54e-5. To go the other way, divide by 2.54e-5 (or multiply by 39370.08).

mil to m conversion table

mil	m
1	2.54e-5
2	5.08e-5
5	0.000127
10	0.000254
25	0.000635
50	0.00127
100	0.00254
250	0.00635
500	0.0127
1000	0.0254

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 3937.008 mil is 0.1 m.

Frequently asked questions

How do you convert thousandth of an inch to metre?

Multiply the value in mil by 2.54e-5 to get m. For example, 10 mil = 0.000254 m.

What is 1 mil in m?

1 mil equals 2.54e-5 m.

Where is this conversion used?