Length Converter
Length is the most fundamental physical dimension, yet it is measured in vastly different ways depending on the discipline. While science relies on the Metric (SI) system, everyday life in the US uses Customary units, and specialized fields like aviation, surveying, and typography retain their own historic standards.
This professional converter unifies these systems, offering instant precision conversion for everything from sub-atomic Picometers to intergalactic Light-years, as well as specialized units like Nautical Miles and Typography Points.
Metric (SI)
StandardMicro & Physics
SciImperial / US
CommonNautical & Surveying
NavAstronomy & Type
SpecialUnderstanding Length Scales
This converter spans an immense range of scales. At the smallest end, we have the Picometer (pm) and Ångström (Å), used to measure atomic bonds and wavelengths of light.
At the human scale, we use Meters and Feet. For navigation on the sea or in the air, the Nautical Mile (based on the circumference of the Earth) is the standard. Finally, for the vastness of space, we rely on the Light-year, the distance light travels in a vacuum in one Julian year (approx 9.46 trillion km).
References
How to Use This Converter
Instantly convert across 25+ distinct units of length.
Select Category
Find your unit in the relevant section (Metric, Imperial, Nautical, or Science).
Enter Value
Type any number. Scientific notation (e.g., 5e-9) is fully supported for very small numbers.
Copy Result
Click the button to copy the precise value to your clipboard.