Knot (kn)
The knot (kn) is a unit of speed based on nautical miles per hour, widely used in both maritime and aviation navigation. The term comes from an early method where sailors used a rope, known as a log line, with evenly spaced knots to gauge a ship’s speed. By counting the number of knots that passed overboard during a set period, they could estimate how fast the vessel was moving. One knot is defined as one nautical mile per hour, equivalent to roughly 1.852 kilometers per hour. Today, the knot is universally adopted for sea and air navigation, providing a consistent and reliable standard for measuring speed in global transportation.
Kilometer per hour (km/h)
The kilometer per hour, symbol km/h, measures speed based on metric distance over time. It became widely used in Europe in the 19th century as road travel and railways expanded, providing a convenient unit for vehicle speed. One kilometer per hour equals 1000 meters traveled in one hour. Today, it is the standard speed unit for road traffic, navigation systems, and weather reporting in most countries, except a few that use miles per hour. Kilometers per hour offers an intuitive way to understand everyday speeds while maintaining metric consistency with distance and time measurements.