Length Converter
Convert between 40+ length units instantly. From quantum physics to cosmic scales.
Popular Length Conversions
Length Measurement Facts & History
The meter was originally defined as 1/10,000,000 of the distance from the equator to the North Pole through Paris.
A light-year equals approximately 9.46 trillion kilometers - the distance light travels in one year.
The Planck length (1.616×10⁻³⁵ m) is the smallest length that has any meaning in physics.
One inch was historically defined as the width of a man's thumb, but is now exactly 2.54 centimeters.
The mile comes from the Latin 'mille passus' meaning 'a thousand paces' of a Roman soldier.
At the quantum scale, the very concept of distance becomes uncertain due to Heisenberg's uncertainty principle.
Length Conversion FAQs
How do I convert meters to feet?
Multiply meters by 3.28084 to get feet. For example, 2 meters = 6.56168 feet. For quick mental calculation, you can use 1 meter ≈ 3.28 feet.
What is the exact conversion from inches to centimeters?
1 inch is exactly 2.54 centimeters. This conversion is internationally standardized and used for all precise measurements.
How many kilometers are in a mile?
1 mile equals 1.60934 kilometers. For approximate conversions, you can use 1 mile ≈ 1.6 kilometers.
What are the most common length units used internationally?
The most common units are meters (metric system) and feet (imperial system). Scientific work uses meters, while construction in the US uses feet and inches.
Universal Converters Length Converter - Professional tool supporting 40+ length units from quantum scale to cosmic distances. Accurate conversions for construction, engineering, science, and everyday measurements.
Convert meters to feet, inches to cm, kilometers to miles, and all common length measurements instantly. Trusted by engineers, architects, students, and DIY enthusiasts worldwide.