How this calculator works
Average velocity divides signed displacement by elapsed time. Final velocity under constant acceleration is a different quantity and depends on the starting velocity. For a journey split into constant-velocity segments, the time-weighted average uses total signed displacement divided by total duration. Segment velocities use m/s and durations use seconds; there must be one positive duration per velocity. Opposite directions have opposite signs.
Formula
v_average = delta x/delta t; v_final = u+at; v_weighted = sum(vi ti)/sum(ti).
Worked example
A displacement of -30 m in 5 s gives -6 m/s average velocity. Travelling at 2 m/s for 3 s and 8 m/s for 1 s gives 14 m in 4 s, averaging 3.5 m/s.
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Frequently asked questions
Is velocity the same as speed?
Speed is the nonnegative magnitude. Velocity also describes direction, represented here by a sign.
When is a simple arithmetic average valid?
For constant velocities lasting equal times. Unequal durations require time weighting.
Does displacement divided by time give the final velocity?
It gives average velocity. Use the acceleration mode when you need the final velocity under a constant acceleration.