Kinematics Calculator

Solve the constant acceleration equations for whichever motion value you leave blank.

Constant acceleration

Initial velocity u (m/s) Final velocity v (m/s)

Acceleration a (m/s²) Time t (s)

Displacement s (m)

Solved value: —

Unknown quantity: —

Equation used: —

Note: —

All values: —

Velocity, acceleration and displacement are signed, so a negative value means motion in the opposite direction.

Common questions about the free online kinematics calculator.

Fill in four of the five values and leave one field blank. The tool then solves for the blank value with the constant acceleration equations.

They are v = u + a t, s = u t + a t squared over 2, v squared = u squared + 2 a s, s = (u + v) t over 2 and s = v t minus a t squared over 2.

The tool tries the simplest equations first, so a value that follows from one multiplication or division is solved that way and shown.

Pick a positive direction and keep it. A negative velocity, acceleration or displacement simply means motion the other way.

If the numbers contradict the equations, such as a negative value under a square root, the tool reports that no real solution exists.

The displacement equation is quadratic in time, so it may have two roots. The tool reports the positive root and notes the alternative.

Yes. Leave the acceleration field blank and the tool uses the change in velocity over time or the displacement equation instead.

Use metres per second, metres per second squared, seconds and metres, or any other set of units as long as it stays consistent.

Yes. Set the initial velocity to zero and the acceleration to 9.81 metres per second squared downwards in your chosen sign convention.

No, the kinematics calculator runs entirely in your browser and stores nothing at all.

Last updated: October 10, 2026