Convert between mm, cm, m, km, inches, feet, yards, miles, and nautical miles
Enter a length value to see conversions
Convert between metric and imperial units for length, weight, temperature, and more
Convert between square millimeters, meters, kilometers, hectares, acres, and more
Convert between m/s, km/h, mph, knots, ft/s, and Mach
Convert between mg, g, kg, tonnes, ounces, pounds, and stones
Length Converter is a free online tool that instantly converts distances and lengths between nine commonly used units: millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles. Whether you need to convert architectural measurements between metric and imperial systems, calculate running distances, or translate international specifications, this tool delivers accurate results in real time. The metric system uses meters as its base unit, with prefixes like milli (1/1000), centi (1/100), and kilo (1000) for different scales. The imperial system uses inches, feet, yards, and miles, with relationships defined as: 12 inches = 1 foot, 3 feet = 1 yard, and 1760 yards = 1 mile. The nautical mile is used in maritime and aviation navigation and equals exactly 1852 meters, approximately one minute of latitude on the Earth's surface. This specialized length converter goes beyond basic unit conversion by showing all nine units simultaneously, letting you compare values at a glance. Enter any value and select the source unit to instantly see the equivalent in every other length unit. All calculations are performed entirely in your browser.
Key conversion factors: 1 inch = 25.4 mm (exact) 1 foot = 0.3048 m (exact) 1 yard = 0.9144 m (exact) 1 mile = 1.609344 km (exact) 1 nautical mile = 1852 m (exact) Examples: 1 meter = 100 cm = 3.281 ft = 39.37 in 1 mile = 5280 ft = 1.609 km = 0.869 nmi 1 km = 0.621 mi = 3281 ft