Velocity & Speed

The working unit for slow mechanical motion in British industry, from colliery winding gear to lifts and conveyor belts.

0.00508 metres per second

Historically used in British ballistics and engineering to measure projectile velocities.

0.3048 metres per second

A playful composite speed unit used humorously to describe extremely sluggish velocities.

0.000166 mph

The metric road speed standard across most of the world, including the Republic of Ireland since 2005.

0.621371 miles per hour

One nautical mile per hour, originating from counting knots on a ship’s log-line.

1.15078 mph

Found in older British literature to describe the steady speed of a walking pace.

3 mph

Used in British aerospace to measure the ratio of speed to the local speed of sound.

Speed of sound (approx. 761 mph at sea level)

The standard SI unit used globally in scientific physics calculations.

2.23694 mph

The enduring legal standard for all British road signs and vehicle speedometers.

1.60934 km/h

The ultimate cosmic speed limit used in foundational physics wave propagation calculations.

299,792,458 metres per second