Convert Between Units of Length
Length measures distance from one point to another and is used across engineering, construction, science, and everyday work. Common units include meters (m), millimeters (mm), kilometers (km), inches (in), feet (ft), and miles. Converting length is one of the most common tasks, especially when drawings, suppliers, and standards use different systems.
About Length Conversions
Helpful context and notes for converting Length units.
Length conversions often fail when conventions are implied rather than written. Many construction drawings assume millimeters without marking the unit, while site plans may use meters. Imperial documents may mix inches and feet, sometimes with fractions. A few exact anchors are useful: 1 inch equals 25.4 mm, and 1 foot equals 304.8 mm. Small rounding errors can matter for fit-up and fabrication, so round at the end based on tolerance rather than habit.
Practical tip: convert fractions to decimals first, then convert units. If you are converting inches to millimeters, use the exact factor 25.4. For quick magnitude checks, 1 meter is about 3.28 feet, but do not use approximations for layout, machining, or anything with tight tolerances. If the converted value looks off by a factor of 1000, suspect mm vs m rather than a bad conversion.
Frequently Asked Questions
Fun Fact
One whale gulp can hit 457,000 kilo-calories, basically Thanksgiving dinner times 2,000.
Supported Units
Common and engineering-specific units supported for this conversion.
- A (angstroms)
- AU (astronimical units)
- clx (centiluxes)
- cm (centimeters)
- chain (Chains)
- datamile (Data Miles)
- dalx (decaluxes)
- dlx (deciluxes)
- ell (Ells)
- fathom (Fathoms)
- ft (feet)
- fermi (Fermis)
- furlong (Furlongs)
- Glx (gigaluxes)
- hlx (hectoluxes)
- in (inches)
- klx (kiloluxes)
- km (kilometers)
- league (Leagues)
- ly (light years)
- link (Links)
- Mlx (megaluxes)
- m (meters)
- μlx (microluxes)
- μm (microns)
- mil (Mils)
- mi (miles)
- mlx (milliluxes)
- mm (millimeters)
- nlx (nanoluxes)
- nm (nanometers)
- nmi (nautical miles)
- pc (parsecs)
- pica (Picas)
- picapt (Pica Points)
- plx (picoluxes)
- rod (Rods)
- survey_ft (Survey Foots)
- survey_mi (Survey Miles)
- Tlx (teraluxes)
- us_fathom (US Fathoms)
- yd (yards)
Unit Categories
Explore the types of units you can convert on this site.