Calculate force from speed: enter mass, starting and final speed, and the time or distance taken to get the average force in newtons or pounds-force.

0 means starting from rest. For a stop, enter the moving speed here and 0 as the final velocity.

Grip estimate and gravity
Rough level-surface model, normal load = mg. Presets are illustrative; measured grip can differ substantially.

Default standard gravity; used for weight, acceleration in g and the optional grip model.

Speed to Force Formula

For constant mass in one-dimensional motion, the following equation gives average net force from the velocity change over a positive time interval.

F = (ΔS / ΔT) × m
  • Where F is the force (N)
  • ΔS is the change in speed (m/s)
  • ΔT is the change in time (s)
  • m is the mass of the moving object (kg)

To calculate net force, divide the signed velocity change by the elapsed time, then multiply by mass. For constant acceleration without direction reversal, the distance method uses F = m(v² − u²)/(2d), where d is positive travel distance. Speed alone does not determine force.

Newtons to Kilonewtons and Pounds-force Conversion Table
Newtons (N) Kilonewtons (kN) Pounds-force (lbf)
10.0010.225
20.0020.450
50.0051.124
100.0102.248
200.0204.496
250.0255.620
300.0306.744
400.0408.992
500.05011.240
750.07516.861
1000.10022.481
1500.15033.721
2000.20044.962
2500.25056.202
3000.30067.443
5000.500112.404
7500.750168.607
10001.000224.809
20002.000449.618
50005.0001124.045
1 N = 0.001 kN; 1 N ≈ 0.224809 lbf. Values rounded to 3 decimals.

Can Speed Be Converted to Force?

Speed is a measure of distance per unit of time, and force measures acceleration times mass. To convert speed to force, you need to convert the speed to acceleration by dividing the change in speed by time. This gives you acceleration. Then, you must multiply by the mass to get force.

How to Convert Speed to Force?

Example Problem:

The following example outlines the steps and information needed to convert speed to force.

First, determine the change in speed. In this example, the initial velocity is 30 m/s and the final velocity is 50 m/s, so the change in speed is 20 m/s.

Next, determine the total time. In this case, the time is measured to be 5 seconds.

Next, determine the mass of the moving object. The object has a measured mass of 3 kg.

Finally, calculate the force using the formula above:

F = (ΔS/ΔT) * m

F = (20/5) * 3

F = 12 N