What is the difference between average velocity and average speed?

Average speed is the total distance travelled divided by time, while average velocity is the total displacement divided by time. Displacement is a vector: it measures how far you are from your starting point in a straight line. If you travel 10 m east and then 10 m west, your displacement is zero and your average velocity is zero, but your average speed is the full 20 m divided by the time taken.

How do you calculate average velocity from multiple segments?

Add all the individual displacements (remembering that displacements in opposite directions cancel) to get the total displacement, then add all the individual times to get the total time. Average velocity equals total displacement divided by total time.

What are the units of average velocity?

The SI unit is metres per second (m/s). This calculator also converts the result to kilometres per hour (km/h) by multiplying m/s by 3.6. For reference, 15 m/s equals 54 km/h.

Average Velocity Calculator

Average velocity is one of the most fundamental quantities in kinematics. It tells you how quickly an object changes its position, measured as the total displacement divided by the total time taken. Unlike average speed, which only measures how far you have travelled regardless of direction, velocity is a vector: if you go 100 m east and then 100 m west in a straight line, your displacement is zero and your average velocity is zero, even though you covered 200 m in total. This distinction matters in physics problems, navigation, and any situation where the direction of movement is important. This calculator works in two modes. In simple mode you enter a single total displacement and a total time, and it returns the average velocity in metres per second and kilometres per hour. In multi-segment mode you can break a journey into up to four separate legs, each with its own displacement and time, and the calculator sums them before computing the overall average velocity. Positive displacements represent movement in one direction and negative displacements represent movement in the opposite direction, so they cancel correctly when added. Enter displacement in metres and time in seconds. The default example uses a total displacement of 120 m covered in 8 s, giving an average velocity of 15.00 m/s, which equals 54.00 km/h. Use this tool for physics homework, motion analysis, or to check your workings quickly.

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Mode

Total displacement

Total time

15.00 m/s

average velocity

In km/h54.00 km/h

Total displacement120.00 m

Total time8.00 s

How it works

Average velocity is defined as total displacement divided by total time: v_avg = Δx / Δt. Displacement is a signed quantity, so segments in opposite directions reduce the total. Time is always positive and all segments add directly. The result in m/s is multiplied by 3.6 to convert to km/h. In multi-segment mode the calculator sums all entered displacements and all entered times before dividing, giving the true average velocity over the whole journey rather than an average of the individual segment velocities.

Worked example

A ball rolls 120 m in a straight line and takes 8 s to do so. Average velocity = 120 m / 8 s = 15.00 m/s. Converting to km/h: 15 x 3.6 = 54.00 km/h. These are the default values pre-filled above, so you can verify the output without changing anything.

Related calculators

Velocity Calculator: find instantaneous velocity using SUVAT variables.
SUVAT Calculator: solve any combination of displacement, velocity, acceleration, and time.
Displacement Calculator: find displacement from initial velocity, acceleration, and time.
Kinetic Energy Calculator: convert velocity into kinetic energy for a given mass.

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