The length unit converter converts drawing and machine dimensions between metric and imperial units. 1 inch = 25.4 mm exactly, 1 mil (thou) = 0.0254 mm = 25.4 µm and 1 foot = 304.8 mm. A 10 ft press brake is 3,048 mm long.
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Results
LiveResult1 in = 25.4 mm
- Micrometer (micron)
- 25,400 µm
- Millimeter
- 25.4 mm
- Centimeter
- 2.54 cm
- Decimeter
- 0.254 dm
- Meter
- 0.0254 m
- Kilometer
- 2.54e-5 km
- Mil / thou
- 1,000 mil
- Inch
- 1 in
- Foot
- 0.083333 ft
- Yard
- 0.027778 yd
- Mile
- 1.578283e-5 mi
- Nautical mile
- 1.37149e-5 nmi
Exact conversion factors (standard gravity g = 9.80665 m/s² where force and mass are linked).
Length unit relationships
1 in = 25.4 mm (exact) · 1 ft = 12 in = 304.8 mm
1 mil = 0.001 in = 25.4 µm
Since 1959 the inch has been defined as exactly 25.4 mm, so metric–imperial conversions are exact. Rounding happens only when values are written on drawings: keep enough decimals for the tolerance (for ±0.1 mm, two decimals in mm or three in inches).
How to use the Length Unit Converter
- Enter the value.
- Choose the units to convert from and to.
- Read all other units in the results panel.
Conversion factors
Value of 1 unit expressed in Millimeter.
| Unit | Symbol | = mm |
|---|---|---|
| Micrometer (micron) | µm | 0.001 |
| Millimeter | mm | 1 |
| Centimeter | cm | 10 |
| Decimeter | dm | 100 |
| Meter | m | 1000 |
| Kilometer | km | 1000000 |
| Mil / thou | mil | 0.0254 |
| Inch | in | 25.4 |
| Foot | ft | 304.8 |
| Yard | yd | 914.4 |
| Mile | mi | 1609344 |
| Nautical mile | nmi | 1852000 |
Frequently asked questions
How many mm is one inch?
Exactly 25.4 mm.
What is a mil or thou?
One thousandth of an inch (0.001 in = 0.0254 mm). It is used for sheet thickness, coatings and tolerances in the US.
How long is a 4 m press brake in feet?
4,000 mm ÷ 304.8 = 13.12 ft. Common press brake lengths: 2.5 m ≈ 8.2 ft, 3.2 m ≈ 10.5 ft, 4 m ≈ 13.1 ft.
Reviewed by the HARSLE engineering team · Last updated October 2026. Results are engineering estimates; confirm critical values with your machine and tooling documentation.
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