Speed Converter

Speed measures distance traveled per unit time. The SI unit is meters per second (m/s), but everyday usage varies widely by domain and country: kilometers per hour (km/h) dominates road speeds in 195 countries, miles per hour (mph) is American/British road usage, knots (nautical miles per hour) are universal in marine and aviation, and Mach (multiples of sound speed, ~343 m/s) is used in supersonic aviation. This converter handles all major speed units: SI standard (m/s, cm/s), road-traffic (km/h, mph), navigation (knot, ft/s), specialty (Mach, Beaufort scale, light-speed for astronomy), and manufacturing feed rates (in/min, yd/min). The Beaufort scale (0–12) describes wind force descriptively, with non-linear conversion to numeric speeds. Use speed conversion for vehicle performance, athletic timing, weather forecasting, marine and aviation navigation, ballistics, and engineering. The km/h is the most-used speed unit globally.

Kilometers per hour is the road-speed standard in 195 countries and the universal weather wind-speed unit.

Meters per second is the SI speed unit, used in physics, engineering, and Olympic athletics measurements.

Miles per hour is the road-speed standard in the United States, the United Kingdom, and several Caribbean countries.

The knot equals one nautical mile per hour and is the universal speed unit for ships and aircraft worldwide.

Mach is the speed of sound multiplier, used in aviation, missile, and supersonic vehicle specifications.

Feet per second is the standard ballistics unit for projectile speeds and American sports analytics.

Centimeters per second measures slow phenomena like ocean currents, biological growth, and geological sedimentation.

Yards per minute is used in American textile manufacturing and traditional industrial production-line specifications.

Inches per minute is the American standard for CNC machining feed rates, 3D printer speeds, and manufacturing.

The Beaufort scale rates wind force from 0 (calm) to 12 (hurricane), used by sailors and meteorologists.

• ✓1 m/s = 3.6 km/h. A common multiplier in physics problems.
• ✓Car speedometers: km/h in most of the world, mph in US and UK (with km/h on EU sold cars).
• ✓Knots are used in aviation and marine. 1 knot = 1.852 km/h.
• ✓Mach is the ratio of an object's speed to the local speed of sound. Mach 1 varies with altitude and temperature.

• ✗Forgetting to divide by 3.6 when going from km/h to m/s.
• ✗Reading a US speedometer as km/h — 70 mph is 112 km/h.
• ✗Treating Mach as a constant speed — sound speed changes with altitude (340 m/s at sea level, 295 m/s at 11 km).
• ✗Confusing speed (m/s) with velocity (m/s with direction) in physics.