Length Converter

This converter supports conversions among 40+ length units from microscopic to cosmic scales, covering the following domains:

International System of Units (SI)

• Base unit: Meter (m) — the base unit of length
• Larger scales: Kilometer (km) = 1000 m, commonly used for geography and traffic distances
• Everyday units: Decimeter (dm) = 0.1 m, Centimeter (cm) = 0.01 m, Millimeter (mm) = 0.001 m
• Microscale: Micrometer (μm) = 10⁻⁶ m (cell size), Nanometer (nm) = 10⁻⁹ m (molecular scale)
• Ultramicro: Picometer (pm) = 10⁻¹² m (atomic scale), Femtometer (fm) = 10⁻¹⁵ m (nuclear scale)

Astronomical units (cosmic scale)

• Light-year (ly): distance light travels in vacuum in one year, about 9.461×10¹⁵ m, used for interstellar distances
• Parsec (pc): about 3.086×10¹⁶ m, commonly used by astronomers
• Astronomical unit (AU): the mean Earth–Sun distance, about 1.496×10¹¹ m, for distances within the solar system

Imperial units (everyday use)

• Inch (in) = 2.54 cm, display sizes, pipe diameters, etc.
• Foot (ft) = 30.48 cm, construction and aviation altitude
• Yard (yd) = 91.44 cm, sports fields and textiles
• Mile (mi) = 1.609 km, road distances (US/UK)
• Chain (ch) = 20.1168 m, land surveying
• Furlong (fur) = 201.168 m, horse racing tracks

Nautical units

• Nautical mile (nmi) = 1852 m, standard for navigation
• Cable (cable) = 185.2 m, short-range nautical measurements
• Fathom (fathom) = 1.8288 m, water depth

Traditional Chinese units

• Li = 500 m, historical road distances
• Zhang = 3.33 m, construction measurement
• Chi = 33.33 cm, furniture and fabric measuring
• Cun = 3.33 cm, fine carpentry and crafts

Specialized units

• Point (pt) = 0.35 mm, printing and typesetting
• Decimillimeter (dmm) = 0.1 mm; historically used in some regions and industries
• Centimillimeter (cmm) = 0.01 mm, optical components fabrication
• Angstrom (Å) = 0.1 nm, interatomic spacing

Usage tips

• Scientific research: prefer SI units
• Engineering: choose metric or imperial per standards
• Navigation/aviation: use nautical mile or foot
• Astronomy: use light-year, parsec, etc.
• Traditional crafts: refer to traditional Chinese units

Note: This converter follows international conventions. Some historical and industry-specific units may vary regionally; refer to relevant standards.