Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Calculate speed from distance and time.
5.0000 m/s
This tool calculates speed (or velocity, for motion in a straight line) from distance traveled and time taken.
Enter the distance (meters) and time (seconds). Speed appears instantly in m/s.
Speed = Distance / Time
This calculator is built for meters and seconds. The distance field is labeled in meters, the time field in seconds, and the answer appears in meters per second. The time must be greater than zero. If your measurements are in other units, convert them before entering, or convert the answer afterward.
Say a cyclist rides 5 kilometers in 25 minutes. These values are hypothetical. Convert first: 5 km = 5,000 m and 25 minutes = 1,500 seconds.
Speed = 5,000 / 1,500 ≈ 3.3333 m/s
In km/h: 3.3333 × 3.6 = 12 km/h
The km/h result checks out with a shortcut: 5 km in 25 minutes is 12 km in 60 minutes. Checking a result with a rough second method is a good habit for any physics calculation.
The calculation divides total distance by total time, so the answer is an average over the whole trip. A runner who sprints, walks, and rests during a 100 m run has a single average value even though the speed at each moment varied. The tool cannot tell you the speed at any particular instant, only the average over the interval you entered. For a trip with several legs, add all the distances and all the times, including stops, and divide the totals. Averaging the leg speeds directly gives the wrong answer unless the time spent on each leg was equal.
The same relationship can be rearranged to solve other unknowns, even though the tool itself only solves for speed:
These are handy for planning, such as estimating travel time or checking a stopwatch reading against a known track distance.
Speed is a scalar (magnitude only); velocity is a vector (magnitude and direction). For straight-line motion, this calculator's result works as either.
Multiply m/s by 2.23694 for mph, or by 3.6 for km/h.
The fields are labeled meters and seconds, so convert to those units first. Alternatively, convert the m/s answer afterward: multiply by 3.6 for km/h.
Average speed over the whole interval, since it divides total distance by total time.
Add up all the distances and all the times, then divide the total distance by the total time. Do not average the individual leg speeds unless each leg took the same time.
Velocity uses displacement, which is zero when you return to the start. Speed still uses the full distance traveled, so it is not zero.
Reference: NIST Weights and Measures