Compression Spring Calculator

Calculate spring rate, deflection, shear stress, and geometry for helical compression springs.

Diameter of the spring wire. Standard gauges range 0.5-16 mm.
mm
Average coil diameter (OD minus wire dia). Spring index C=D/d should be 4-12.
mm
Coils that actively deflect. Total coils = active + 2 for closed/ground ends.
Material determines shear modulus (G). Music wire is strongest; stainless for corrosion.
The compression force applied to the spring.
N

Results

Spring Rate (k)-N/mm
Deflection-mm
Shear Stress (Wahl corrected)-MPa
Solid Height-mm
Suggested Free Length-mm
References: Wahl, A.M. — Mechanical Springs, SMI Handbook of Spring Design.