Average Velocity Calculator
Average velocity from total displacement and time, from several trip legs, or from initial and final velocity, with average speed and a leg-by-leg table.
Average velocity is total displacement divided by total time — not the average of the speeds along the way. This calculator handles a single trip, a trip broken into legs (each given as velocity and distance, velocity and time, or displacement and time), and motion under constant acceleration. For multi-leg trips it also reports average speed, which uses the total distance travelled instead of the net displacement.
How to use this tool
- Pick the method that matches what you know.
- Choose the distance and time units; velocities use the same pair, so kilometres and hours means km/h.
- Enter the total displacement and time, or type one leg per line, or enter the initial and final velocity.
- Read the average velocity, its conversions and, for legs, the leg-by-leg table.
Formula
v̄ = Δx_total ÷ t_total = (Δx₁ + Δx₂ + …) ÷ (t₁ + t₂ + …) · v̄ = (u + v) ÷ 2
Displacements carry a sign, so legs in opposite directions cancel out. Average speed replaces each Δx with its size |Δx|. The (u + v) ÷ 2 shortcut applies only when the acceleration is constant. Each leg is straight and has no unrecorded reversal; split a turn into separate legs. A velocity-distance leg needs positive distance. Use velocity-time with zero velocity for a pause. Lines accept decimal/scientific numbers and one comma, semicolon or whitespace separator.
Example
You drive 60 km at 30 km/h, then another 60 km at 60 km/h. The legs take 2 h and 1 h, so the average velocity is 120 km ÷ 3 h = 40 km/h (about 11.11 m/s) — not 45 km/h, because you spend twice as long at the slower speed.
Frequently asked questions
Why isn’t average velocity the average of the speeds?
An arithmetic mean is valid for equal-duration legs only when signed velocities are averaged. For equal distances in the same direction, the slower leg occupies more time. If a trip reverses direction, track signed displacement separately from total distance.
Can my average velocity be zero even though I moved?
Yes. If you end where you started, the net displacement is zero, so average velocity is zero while average speed is not. Enter the return leg with a negative velocity or displacement to see both.
Is (u + v) ÷ 2 always correct?
Only for constant acceleration, such as a car braking evenly or a dropped object before drag matters. For anything else, divide total displacement by total time.
Last updated: 2026-10-30