Constant Force Helical Compression Spring Design Calculator


A constant force helical compression spring design calculator able to calculate the constant or rate of a helical compression spring design as well as safe maximum load and safe maximum travel.

Spring rate or spring constant is the "Master" when it comes to your helical compression spring design. Your helical compression spring undergoes a load while traveling down to your desired loaded height. Follow the example shown below which demonstrates the formula found in Hooke’s Law.

Ex. You have a spring that is 2” (two inches) long. You need this spring to travel 1.5” (one and a half inches) down to a loaded height of 0.5” (half inch). If you have a spring rate of 1 lbf/in (one pound of force per inch of travel), what amount of force or load will you have to apply to this spring for it travel down to your desired loaded height? Please follow the helical compression spring design formula below and view the image which will demonstrate and explain the formula.

A ruler measuring two inches with three springs to the right of it. One at free length, another at a loaded height, and another at solid height along with the explanation and formula to calculate the constant force increase

k = F ÷ x

Where as:
k = Spring Constant (Spring Rate)
F = Force (Load)
x = Distance traveled

Once we insert the values into such formula, you must proceed as follows using reverse math to get the value of F.

k = 1
F = unknown value
x = 1.5

2 = F ÷ 1.5
F = 2 * 1.5
F = 1.5