Hooke's Law Calculator
Enter any two of spring force, spring constant and displacement to solve Hooke's law, F = k x x. The tool finds the missing value and the elastic potential energy stored in the spring.
How to use the Hooke's law calculator
- Choose whether to solve for force, spring constant or displacement.
- Enter the two known values in SI units (N, N/m, m).
- Read the missing value and the elastic potential energy in joules.
Examples
Force from constant and stretch
k = 200 N/m, x = 0.1 m
F = 20 N, energy = 1 J
Spring constant from force and stretch
F = 50 N, x = 0.25 m
k = 200 N/m, energy = 6.25 J
Frequently asked questions
What is Hooke's law?
Hooke's law states that the force a spring exerts is proportional to how far it is stretched or compressed: F = k x x, where k is the spring constant and x is the displacement.
How do I find the spring constant?
Rearrange Hooke's law to k = F / x. Divide the spring force by the displacement to get the stiffness in newtons per metre.
How is elastic potential energy calculated?
The energy stored in a stretched spring is one half times the spring constant times the displacement squared: PE = 0.5 x k x x^2, measured in joules.
What units should I use?
Use newtons for force, newtons per metre for the spring constant and metres for displacement. Energy then comes out in joules.
Does Hooke's law always hold?
Only within the elastic limit of the spring. Stretch it too far and it deforms permanently, so the linear relationship F = k x x no longer applies.
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