Spring Constant Calculator (k = F/x)

k = F / x. Determine spring stiffness from a known force and displacement.

Inputs

Result

Spring constant
500.000 N/m
Period for 1 kg mass: 0.281 s.
  • Applied force50 N
  • Displacement0.1 m
  • Spring constant k500.0000 N/m
  • k in N/cm5.0000
  • Period (1 kg, m on spring)0.2810 s

Step-by-step

  1. k = F / x = 50 / 0.1 = 500.0000 N/m.
  2. T = 2π √(m/k) for spring oscillator; for m = 1 kg: 0.2810 s.

How to use this calculator

  • Apply known force.
  • Measure displacement.
  • Read k.

About this calculator

Spring constant k measures stiffness: how much force per unit displacement. Stiff springs (k = 1000+ N/m): door closers, car suspension. Soft springs (k = 1-50 N/m): toys, foam. Determine experimentally by hanging a known weight and measuring stretch. The relationship F = kx (Hooke's) is a defining property — non-Hookean materials require more complex models.

Frequently asked

For ideal springs in elastic region, exact. Real springs may be slightly nonlinear at extremes; linearize around operating point.

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