Hooke's Law Calculator — F = kx

Hooke's law: the force a spring exerts is proportional to how far it is stretched or compressed. The spring constant k measures stiffness.

$F = kx$

Solve for

Spring constant (k)

Unit

Stretch / compression (x)

Unit

Result unit

How to interpret the result

A 200 N/m spring stretched 0.15 m pulls back with 30 N. Stiffer springs (larger k) give more force for the same stretch.