Find velocity, in every unit at once.
Pick a method, enter what you know in any units, and get the velocity instantly in m/s, km/h and mph. Use plain average velocity (distance over time) or final velocity when something is accelerating at a constant rate.
What do you know?
Enter distance and time to find the average velocity. The velocity field shows the result.
What this velocity means
Velocity over time
How velocity changes as time passes
The same velocity in every unit
Velocity scorecard
Velocity and distance over time
Velocity and the distance covered at points along the motion.
| Time | Velocity (m/s) | Velocity (km/h) | Distance covered |
|---|
Velocity, explained
Velocity vs Speed
Velocity is a vector, it has both magnitude and direction. Speed is the scalar magnitude only. When motion is along a single direction (which is what this calculator assumes), the magnitude of velocity equals speed. For 2D or 3D motion, you would need separate calculators for each axis.
Unit Conversions
1 m/s = 3.6 km/h = 2.237 mph = 1.944 knots. The calculator shows m/s, km/h, and mph automatically so you can compare to road signs and aviation references. A 100-meter sprinter at world-class level (sub-10 seconds) hits about 10 m/s, which is 36 km/h or 22.4 mph.
Real-World Velocity Examples
Walking: 1.4 m/s (5 km/h, 3.1 mph). Jogging: 3 m/s. Cycling: 6-12 m/s. Highway driving: 27-33 m/s (100-120 km/h). Commercial jet cruise: 250 m/s (900 km/h). Speed of sound at sea level: 343 m/s. Use these as sanity checks for your calculation.
Average vs Instantaneous Velocity
This calculator returns average velocity over the entire distance and time. Instantaneous velocity (the value at a single moment) requires calculus, taking the derivative of position with respect to time. If your motion involves accelerating from rest, the average is roughly half the final velocity, not the same as it.
Common questions
Why is velocity sometimes negative?
Negative velocity indicates motion in the negative direction relative to your chosen positive axis. This calculator returns positive values when distance and time are positive, the sign is purely conventional.
What's the difference between average and instantaneous velocity?
Average velocity is total distance divided by total time. Instantaneous velocity is the speed at one specific moment, computed via the derivative of position. For constant-velocity motion, both are equal.
Can I use this for vertical motion (falling objects)?
Yes, but remember gravity is accelerating you. For free fall, use v = g*t (where g = 9.81 m/s²) to find final velocity, or use the Acceleration Calculator to model the change.
What units should I use?
Enter distance in meters and time in seconds for SI-unit output. The calculator also converts to km/h and mph automatically.
How does this relate to the speed of light?
Speed of light is 299,792,458 m/s, about 1 billion km/h. Nothing with mass can reach it. For everyday velocity questions, this calculator is fine; relativistic effects only matter above ~10% the speed of light.
Results assume motion along a single straight line, so the magnitude of velocity equals speed. Average velocity mode treats speed as constant, and acceleration mode treats acceleration as constant. Real motion varies with friction, air resistance and changing forces. Use these figures for planning and study.