Calculate collapsed and extended shock length, plus mount and axle spacing, from any 2 inputs in inches, feet, cm, or m for suspension setup.

Shock Length Calculator

Enter any 2 values to calculate the missing variables

Shock Length Formula

The following two example problems outline the steps and information needed to calculate the Shock Length.

SHOCK = (D1 - D2) - 1
  • Where SHOCK is the Shock Length (in)
  • D1 is the distance between the upper shock mount and lower shock mount (in) 
  • D2 is the distance between the bump stop and the axle 

How to Calculate Shock Length?

The following example problems outline how to calculate Shock Length.

Example Problem #1:

  1. First, determine the distance between the upper shock mount and lower shock mount (in).
    • The distance between the upper shock mount and lower shock mount (in) is given as: 6.
  2. Next, determine the distance between the bump stop and the axle.
    • The distance between the bump stop and the axle is provided as: 4.
  3. Finally, calculate the Shock Length using the equation above: 

SHOCK = (D1 – D2) – 1

The values provided above are inserted into the equation below and computed.

SHOCK = (6-4) – 1 = 1 (in)


Example Problem #2: 

For this problem, the variables required are provided below:

distance between the upper shock mount and lower shock mount (in) = 3

distance between the bump stop and the axle = 1

Test your knowledge using the equation and check your answer with the calculator..

SHOCK = (D1 – D2) – 1 = ?