# Helical Spring Rate Calculator

The spring rate refers to the amount of weight that is needed to compress a spring one inch. The helical spring rate calculator helps you to calculate the Spring Rate (d) and the Spring Index (C) using the known values of spring diameter, wire diameter, modulus of rigidity and number of active coils. Enter the required details in this calculator to know the Helical spring rate and spring index.

### Example:

Calculate spring rate for spring diameter as 5m, wire diameter as 6m, modulus of rigidity as 8 and number of active coils as 9.

#### Solution:

Spring Index=(D/d)^{3}

= 0.8333333333333334

Helical Spring Rate = (8 x 6)/(8 x 0.8333333333333334 x 9)

= 1.1519999999999997