Length Converter

The length converter changes a value between 14 supported distance and length units, ranging from nanometers to parsecs. Every unit is represented internally by a fixed factor relative to the meter, allowing the same conversion method to work for metric, imperial, nautical and astronomical units.

How it works

Enter a numeric value, choose the source unit and destination unit, then select Convert. The calculator first expresses the entered quantity using the source unit's meter factor and then divides by the destination unit's meter factor. The swap control reverses the selected units without changing the entered value.

The formula

Supported units are nanometer, micrometer, millimeter, centimeter, meter, kilometer, inch, foot, yard, mile, nautical mile, astronomical unit, light year and parsec. Examples of stored factors are 1 cm = 0.01 m, 1 in = 0.0254 m, 1 mi = 1609.344 m and 1 nmi = 1852 m.

Worked example

For 100 centimeters to inches, the calculation is 100 × 0.01 ÷ 0.0254 = 39.37007874 inches. Similarly, 1 nautical mile equals exactly 1.852 kilometers using the factors implemented by the calculator.

The conversion is mathematical and uses the fixed factors implemented by the calculator. When a measurement comes from a physical instrument, its real-world accuracy also depends on the precision and calibration of that measurement.

Frequently asked questions