Length Unit Converter

Length Converter

Enter a value and select units to convert
Enter a value and select units to convert

The length converter allows you to convert between different units of length or distance, from microscopic scales like nanometers to astronomical distances like light years. Whether you're working with the metric system, imperial units, or specialized scientific measurements, this tool provides quick and accurate conversions between 50+ length units.

Common Measurement Systems

Metric System (SI)

The International System of Units (SI) is the modern form of the metric system and is the most widely used system of measurement globally. Base unit: meter (m)

  • Prefixes are used to create multiples and submultiples: kilo- (1,000), centi- (0.01), milli- (0.001), etc.
  • Common units: millimeter (mm), centimeter (cm), meter (m), kilometer (km)

Imperial System

Used primarily in the United States and a few other countries. Based on historically standardized units.

  • Common units: inch (in), foot (ft), yard (yd), mile (mi)
  • 1 foot = 12 inches, 1 yard = 3 feet, 1 mile = 1,760 yards

Astronomical Units

Used for measuring vast distances in space.

  • Light-year (ly): distance light travels in one year (9.46 trillion km)
  • Astronomical Unit (AU): average distance from Earth to Sun (149.6 million km)
  • Parsec (pc): approximately 3.26 light-years

Typography/Digital Units

Used in printing, typography, and digital design.

  • Point (pt): approximately 1/72 of an inch
  • Pica (pc): 12 points, or about 1/6 of an inch
  • Twip: 1/20 of a point, or 1/1440 of an inch

Scientific Units

Often used in physics, chemistry, and other scientific fields.

  • Angstrom (Å): 0.1 nanometers, often used for atomic scales
  • Femtometer/Fermi (fm): 10^-15 meters, used in nuclear physics

Maritime Units

Specialized units for maritime navigation and depth measurement.

  • Nautical mile (nmi): approximately 1.852 kilometers
  • Fathom (ftm): 6 feet, traditionally used for measuring water depth

Common Length Conversions

From To Multiply By
Inches Centimeters 2.54
Feet Meters 0.3048
Yards Meters 0.9144
Miles Kilometers 1.60934
Nautical Miles Kilometers 1.852
Millimeters Inches 0.03937
Centimeters Inches 0.3937
Meters Feet 3.28084
Kilometers Miles 0.62137
Angstroms Nanometers 0.1
Light Years Kilometers 9.461 × 10^12
Astronomical Units Kilometers 1.496 × 10^8