Length Converter
Instantly convert between metric and imperial length units. This free calculator supports millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles with precise conversion factors.
Length conversion is one of the most common unit conversions needed in everyday life, science, and engineering. The metric system (mm, cm, m, km) is based on powers of 10, making conversions within the system simple. The imperial system (in, ft, yd, mi) uses different ratios between units.
Key Conversion Factors
- 1 inch = 25.4 mm (exact, by definition)
- 1 foot = 12 inches = 0.3048 m (exact)
- 1 yard = 3 feet = 0.9144 m (exact)
- 1 mile = 5,280 feet = 1,609.344 m (exact)
- 1 kilometer = 1,000 meters
All conversions in this calculator use the exact international definitions, ensuring maximum accuracy for engineering, scientific, and everyday calculations.