Length Converter

Convert any length unit to any other in seconds with our Length Converter. It supports metric, imperial, and scientific/astronomy units, so you can switch from tiny measurements to huge distances without doing manual math.

20+ length units supported

• Ångström (Å)
• Picometers (pm)
• Nanometers (nm)
• Micrometers (μm)
• Millimeters (mm)
• Centimeters (cm)
• Decimeters (dm)
• Meters (m)
• Meters + centimeters
• Kilometers (km)
• Thousandths of an inch (mil / thou)
• Inches (in)
• Feet (ft)
• Feet + inches
• Yards (yd)
• Miles (mi)
• Nautical miles (nmi)
• Sun radii (R☉)
• Light years (ly)
• Astronomical units (au)
• Parsecs (pc)

How this length conversion calculator works

Just type your value and choose your units. You can add up to 11 units at once, and the converter updates in real time, showing the result in every unit you select. Want a different unit? Click the unit name to swap it instantly.

Length Conversion Table

Want the exact conversion factors between the most commonly used length units? Use this quick table to compare metric and imperial measurements at a glance—perfect for homework, DIY projects, travel, maps, and everyday conversions.

Metric “ladder” (big → small)

km → hm → dam → m → dm → cm → mm → µm → nm → pm

Each step right = ×10 (smaller units)

Each step left = ÷10 (bigger units)

km hm dam m dm cm mm µm nm pm

÷10 ÷10 ÷10 ÷10 ÷10 ÷10 ÷10 ÷10 ÷10

×10 ×10 ×10 ×10 ×10 ×10 ×10 ×10 ×10

Conversion table (all to meters)

Unit Symbol Equals in meters

kilometer km 1 km = 1,000 m

hectometer hm 1 hm = 100 m

decameter dam 1 dam = 10 m

meter m 1 m = 1 m

decimeter dm 1 dm = 0.1 m

centimeter cm 1 cm = 0.01 m

millimeter mm 1 mm = 0.001 m

micrometer µm 1 µm = 0.000001 m (10⁻⁶ m)

nanometer nm 1 nm = 0.000000001 m (10⁻⁹ m)

picometer pm 1 pm = 0.000000000001 m (10⁻¹² m)