### Compression Spring Constant Equation and Calculator

This calculator will determine the spring rate constant related to a compression spring from basic geometry and material data input. Default units are shown in inches, etc however SI (metric) can be used.

This equation will determine (estimate) the Spring Rate (k) of a compression spring. Spring rate is best determined by test and measurement techniques.

**Open Compression Spring Constant (k) Calculator**

(*This calculator requires a java - enabled browser*)

Equation:

k = Gd^{4}/[8nD^{3}]

Where:

k = constant, pounds of load per inch of deflectionG = modulus of rigidity of spring material, pounds per square inch

d = wire diameter, inches

n = number of active coils, which is the number of coils subjected to flexure (always less than the total number of coils)

D = mean coil diameter, inches = Outer Diameter - Wire Diameter

G** is calculated from the spring materials Elastic modulus and Poisson Ratio n **

G = E/(2(1 + v)

*The pitch of the spring coil can be found by *

C_{p} = L_{f} / n_{c}

Where:

L_{f }= Uncompressed length of spring

n_{c} = Number of coils

The angle of the spring coil relativeto the mounting base is found:

f = atan [ C_{p} / p D ]

Compression Spring Design Suggestions

Related

- Compression Spring Calculator
- Compression Spring "k" Constant Calculator
- Compression Spring Assembly Operating Life and Reliability Equations and Calculator
- Conical Helical Compression Spring Design Equations and Calculator
- Constant Force Spring Design & Equations
- Helical Compression Springs Engineering and Design
- Extension Spring "k" Constant Calculator
- Extension Spring Calculator
- Extension Spring Normal Load Tolerances load / force Specifications
- Torsion Spring Calculator
- Torsion Applied Spring Stiffness Constant Equations and Calculator
- Coil-Diameter Tolerances of Torsion Springs Specifications
- Series Mounted Springs Stiffness Constant Equations and Calculator
- Spring Helix Wire Length Formula and Calculator
- Spring Properties and Material