Velocity Calculator
Velocity is displacement divided by time: v = d ÷ t. Enter any two of distance, time, and velocity to solve for the third — in m/s, km/h, mph, or ft/s.
Example: with Solve for Velocity (v = d ÷ t) · Distance 100 · Distance unit meters (m) · Time (seconds) 12.5 · Velocity (for distance & time modes) 8 · Velocity unit m/s → Result: 8.00 m/s.
Computed by the calculator below using its default values. Change any input to see your own numbers.
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Check it outHow to find velocity
Velocity is displacement divided by time: v = d ÷ t. A sprinter covering 100 m in 12.5 s runs 100 ÷ 12.5 = 8 m/s, which is 28.8 km/h or about 17.9 mph. The same equation is how you calculate average velocity for a whole trip — total displacement over total time — so 150 km driven in 2 hours averages 75 km/h no matter how the speed varied along the way.
The velocity equation rearranges to solve for anything: distance d = v × t (60 mph held for an hour covers 60 miles) and time t = d ÷ v (100 m at 8 m/s takes 12.5 s). Physics classes work in m/s; multiply m/s by 3.6 for km/h or by 2.23694 for mph. If you need final velocity under constant acceleration, that’s a different formula — v = u + at — covered in the FAQ below.
How it’s calculated
Velocity mode computes v = d ÷ t after converting distance to meters, with time in seconds; distance mode computes d = v × t; time mode computes t = d ÷ v. Unit constants: 1 km = 1,000 m, 1 mile = 1,609.344 m, 1 ft = 0.3048 m, 1 mph = 0.44704 m/s, 1 km/h = 1 ÷ 3.6 m/s, 1 ft/s = 0.3048 m/s. Results are shown in your selected unit plus m/s, km/h, mph, and ft/s.
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Mixing units — dividing kilometers by seconds gives km/s, not km/h. Convert first (90 minutes = 5,400 s).
- Using total path length when the question asks for velocity — velocity uses straight-line displacement, so one full lap of a track has zero average velocity.
- Averaging two speeds for a round trip — over equal distances the answer is not (v1 + v2) ÷ 2; divide total distance by total time instead.
Frequently asked questions
What is the velocity formula?
Velocity equals displacement divided by time: v = d ÷ t. In SI units that gives meters per second — 8 m/s means you cover 8 meters each second.
How do you find velocity?
Divide the distance (displacement) by the time it took. A car covering 400 m in 50 s has v = 400 ÷ 50 = 8 m/s, about 17.9 mph.
How do I calculate final velocity?
Under constant acceleration, final velocity is v = u + at. Starting from rest (u = 0) and accelerating at 3 m/s² for 5 s gives v = 0 + 3 × 5 = 15 m/s.
What is the difference between speed and velocity?
Speed is distance over time and is always positive; velocity is displacement over time and includes direction. Walk 50 m east and 50 m back in 100 s: average speed 1 m/s, average velocity 0.
How do I convert m/s to km/h or mph?
Multiply m/s by 3.6 for km/h and by 2.23694 for mph. So 10 m/s = 36 km/h ≈ 22.4 mph.