Speed, Distance and Time Formula

Speed, distance and time are linked by one formula, rearranged three ways.

Formulas

speed = distance ÷ time

distance = speed × time

time = distance ÷ speed

average speed = total distance ÷ total time

Average speed trap

Out at 60 km/h, back the same 60 km at 40 km/h

  1. Time out: 1 h; time back: 1.5 h
  2. Total: 120 km in 2.5 h

Average speed 48 km/h — not 50. Average speed is total distance over total time, not the mean of the speeds.

Unit tips

  • Minutes to hours: divide by 60.
  • km/h to m/s: divide by 3.6.
  • mph to km/h: multiply by 1.609344.