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Convert between meters, kilometers, miles, feet, inches, light years and 20+ more units instantly.
The metric system is based on powers of 10. The base unit is the metre (m). Prefixes like kilo (×1000), centi (÷100), and milli (÷1000) make conversions straightforward by simply moving the decimal point.
Used primarily in the US and UK. Key units: 1 foot = 12 inches, 1 yard = 3 feet, 1 mile = 5,280 feet = 1,760 yards. The conversion factor between metric and imperial is 1 inch = 2.54 cm exactly.
Astronomers use light-years (distance light travels in one year ≈ 9.461 × 10¹⁵ m), parsecs (≈ 3.086 × 10¹⁶ m), and AU (Earth–Sun distance ≈ 1.496 × 10¹¹ m) to measure vast cosmic distances.
One nautical mile equals exactly 1,852 metres and corresponds to one minute of arc of latitude. It is used in marine and air navigation. A knot is one nautical mile per hour.