Length Converter
Convert between 20 length units: metric, imperial, nautical and astronomical, with live results and the exact formula shown for every conversion.
How length conversion works
Every unit is converted through meters, the SI base unit. Each unit stores one fixed factor (for example 1 inch = 0.0254 m), so any pair converts in a single step: value x from-factor / to-factor. That is why results are exact, with no rounding drift between chained conversions.
Metric, imperial and specialty units
Metric units scale by powers of ten, while imperial units use fixed ratios (12 inches per foot, 3 feet per yard, 1760 yards per mile). This page also covers nautical miles for aviation and sailing, plus astronomical units, light-years and parsecs for space distances, and screen units (px, pt, em) for web design.