Average Velocity Calculator

Average speed: v = Δs/Δt

Average speed is the total distance traveled divided by the total time: v = Δs/Δt. The SI unit is m/s, but km/h is more common for everyday travel (divide km/h by 3.6 to get m/s). A crucial point: average speed is not the average of the speeds. Classic example: you drive 60 km at 60 km/h (1 hour) and return at 30 km/h (2 hours). Total: 120 km in 3 h, so v_avg = 40 km/h — not 45. Because more time is spent at the slower speed, it dominates the average. Average speed also differs from instantaneous speed (the value a derivative or speedometer gives at one moment).

Applications

Personal running/cycling pace, flight planning (groundspeed vs airspeed, since wind shifts the result), boating (speed over water vs over ground), road-trip ETA, race analysis. Scalar vs vector matters: running 100 m out and 100 m back in 1 min gives a scalar average speed of 12 km/h but a vector average velocity of 0 — you ended where you started.

FAQ

Why isn't average speed the average of two speeds? Because each speed segment may take a different amount of time. The slower leg takes longer and therefore weighs more in the average.

How do I convert km/h to m/s? Divide by 3.6. Example: 108 km/h ÷ 3.6 = 30 m/s.

Speed or velocity? Speed is a scalar (magnitude only). Velocity is a vector (magnitude + direction). On a round trip, the average velocity can be zero while the average speed is not.