Length Converter
Convert between meters, kilometers, centimeters, millimeters, miles, yards, feet, inches, and nautical miles. All conversions use exact, definitionally-fixed SI factors.
All Length and Distance Converters
Choose a specific conversion for a dedicated page with formula, examples, and tables.
- Kilometers to Mileskm → mi
- Miles to Kilometersmi → km
- Meters to Feetm → ft
- Feet to Metersft → m
- Centimeters to Inchescm → in
- Inches to Centimetersin → cm
- Millimeters to Inchesmm → in
- Inches to Millimetersin → mm
- Yards to Metersyd → m
- Meters to Yardsm → yd
- Nautical Miles to Kilometersnmi → km
- Kilometers to Nautical Mileskm → nmi
- Micrometers to Millimetersµm → mm
- Nanometers to Micrometersnm → µm
- Angstroms to NanometersÅ → nm
- Furlongs to Metersfur → m
- Chains to Metersch → m
- Rods to Metersrd → m
- Fathoms to Metersftm → m
About Length Units
Length is the most fundamental spatial dimension, and human societies have measured it for thousands of years. The modern international system rests on the meter, which since 1983 has been defined by the speed of light. From this single base unit, every other length unit — from the nanometer to the light-year — can be derived with exact precision.
In daily life, the two most common systems are the metric system (meter-based, used almost everywhere) and the US customary/imperial system (foot-based, still used in the United States, the United Kingdom for some purposes, and a few other countries). Converting between them is straightforward because the relationships are fixed by international agreement.
Key exact relationships
- 1 inch = 2.54 centimeters exactly
- 1 foot = 0.3048 meters exactly
- 1 yard = 0.9144 meters exactly
- 1 international mile = 1,609.344 meters exactly
- 1 nautical mile = 1,852 meters exactly
Because all of these are exact, any conversion that uses only these factors produces an exact result (subject to floating-point representation limits in the calculation). Where precision matters — surveying, engineering, navigation — M-Convert uses these exact values without rounding.
Frequently Asked Questions
How many feet are in a meter?
One meter equals approximately 3.280839895013123 feet. The exact factor is 1 / 0.3048, because one international foot is defined as exactly 0.3048 meters.
Is a mile longer than a kilometer?
Yes. One mile equals approximately 1.609 kilometers. A mile is about 60.9% longer than a kilometer.
What is the difference between a nautical mile and a statute mile?
A nautical mile is exactly 1,852 meters and is used in aviation and maritime navigation. A statute mile (international mile) is exactly 1,609.344 meters and is used for road distances in the US and UK.
How accurate are these conversions?
All conversions in this category use exact, definitionally-fixed factors. Results are computed in double-precision floating point, which provides approximately 15–16 significant decimal digits of accuracy.
Can I convert from any unit to any other unit?
Yes. The converter above supports all eleven length units in any combination. For specific pairs, dedicated pages provide formula, worked examples, and conversion tables.