Length Converter

How to use Length Converter

Enter a measurement, select its current unit and target unit, then convert. Negative values are allowed when they represent coordinates or differences.

Supported length units

The converter supports millimeters, centimeters, meters, kilometers, inches, feet, yards, statute miles, and nautical miles. Metric units scale by powers of ten. Imperial and US customary length units use fixed international definitions, while the nautical mile is defined separately for navigation.

How conversion works

Each input is first converted to meters using its fixed factor, then divided by the target unit’s meter factor. Several important exact definitions include one inch = 0.0254 meter, one foot = 0.3048 meter, one yard = 0.9144 meter, one statute mile = 1,609.344 meters, and one nautical mile = 1,852 meters.

Worked example

Convert one meter to feet. Divide 1 meter by 0.3048 meter per foot: 1 ÷ 0.3048 = 3.28083989501 feet. Converting the displayed rounded result back to meters should produce approximately one meter, although copying fewer displayed digits can introduce a small rounding difference.

Statute and nautical miles

A statute mile is the ordinary land-distance mile used in the United States and United Kingdom. A nautical mile is longer and is used in marine and aviation contexts. Do not substitute one for the other: one nautical mile is about 1.15078 statute miles.

Negative values and measurements

Negative values are accepted because they can represent coordinates, offsets, elevations relative to a reference, or changes in position. A physical object’s length is normally nonnegative, so review the context when converting a negative input.

Accuracy and limitations

The result displays up to twelve significant digits. Floating-point arithmetic can create tiny representation differences, especially after repeated conversions. The page converts scalar lengths only; it does not convert areas, volumes, compound feet-and-inches notation, map scale, or geographic distance along Earth’s surface.