Speed Conversion Calculator

Speed describes distance traveled per unit of time, but different countries and activities use different unit systems. Kilometers per hour appear on road signs and vehicle speedometers in most of the world, while miles per hour are common in the United States and United Kingdom. Meters per second are the SI unit used in science and engineering. Knots are standard in aviation and marine navigation, and feet per second appear in some engineering and ballistics contexts. This calculator converts every input through meters per second. One kilometer per hour equals one divided by 3.6 meters per second. One mile per hour equals exactly 0.44704 meters per second, based on the international mile and a 3,600-second hour. One knot equals one nautical mile per hour, or approximately 0.5144444444 meters per second. One foot per second equals exactly 0.3048 meters per second. Using a single base unit keeps conversions between any two choices consistent. To convert manually, multiply the source value by its meters-per-second factor, then divide by the target unit's factor. For example, 100 kilometers per hour is 27.77777778 meters per second. Dividing that by 0.44704 gives approximately 62.13711922 miles per hour. The calculator performs both operations and formats the result with useful precision. Speed is a rate, so converting its unit does not change the underlying motion. A car traveling at 60 mph has the same speed when described as 96.56064 km/h. However, speed and velocity are not identical in physics: speed is magnitude only, while velocity also includes direction. This tool converts scalar speed values and does not represent direction, acceleration, or travel time. Use speed conversion for route planning, running and cycling pace comparisons, weather reports, vehicle specifications, scientific data, aviation, shipping, and engineering documentation. The result is only as accurate as the entered measurement. Displayed decimal digits help prevent conversion rounding from dominating the answer, but they do not add precision to the source. For safety-critical navigation or engineering, apply the standards, significant figures, and approved constants required by your field.