Logo
Login Register
📏

Length Converter

Convert between mm, cm, m, km, inches, feet, yards, and miles.

ddd
Result
in
Quick Conversion Table
Based on current input
Unit Value

Length Conversion Guide

Cheat Sheet
  • 1 m = 100 cm = 1,000 mm
  • 1 km = 1,000 m
  • 1 in = 2.54 cm (exact)
  • 1 ft = 12 in = 0.3048 m (exact)
  • 1 yd = 3 ft = 0.9144 m (exact)
  • 1 mi = 5,280 ft ≈ 1.609344 km (exact definition)

Exact SI ties: inch, foot, yard, and mile are defined via the meter, so conversions are precise.

How it’s calculated

We convert through a base unit: meter (m). Your input converts to meters with an exact factor, then meters convert to the target unit. This keeps results consistent (e.g., ft → m → in).

Examples: 10 ft → 10 × 0.3048 = 3.048 m → 120 in.   25 cm → 0.25 m → 9.84252 in.
When to use which unit
  • mm / cm: small parts, woodworking tolerances, product specs.
  • m / km: everyday metric, road distances.
  • in / ft / yd: construction, furniture, US/UK specs.
  • mi: long road distances in US/UK.

Length – Full History