Enter the torsion spring constant and angle of twist into the calculator to determine the torsion bar spring energy.

Torsion Bar Spring Energy Formula

The following equation is used to calculate the Torsion Bar Spring Energy.

U = 1/2 * k * a^2
  • Where U is the torsion spring energy storage (joules)
  • k is the torsion spring constant (N-m/radian)
  • a is the angle of twist (radians)

To calculate the torsion bar spring energy, multiply the torsion spring constant by the angle of twist squared, then divide by 2.

What is a Torsion Bar Spring Energy?


A torsion bar spring energy measures the potential energy store with a spiral/torsional spring that has been twisted by a certain angle.

How to Calculate Torsion Bar Spring Energy?

Example Problem:

The following example outlines the steps and information needed to calculate Torsion Bar Spring Energy.

First, determine the torsion spring constant. In this example, with the help of the calculator linked above, the spring constant is found to be 50 N-m/radian.

Next, determine the angle of the twist. In this case, the angle of twist is measured to be 3 radians.

Finally, calculate the torsion bar spring energy using the formula above:

U = 1/2 * k * a

U = 1/2 * 50*3^2

U = 225 Newton-meters=Joules


What factors can affect the torsion spring constant?

The torsion spring constant can be influenced by several factors including the material of the spring, the diameter and length of the spring, and the overall design of the spring such as coil diameter and the number of coils.

How does the angle of twist impact the energy stored in a torsion bar spring?

The energy stored in a torsion bar spring increases with the square of the angle of twist. This means that as the angle of twist grows, the energy stored in the spring increases exponentially, following the formula U = 1/2 * k * a^2, where ‘a’ represents the angle of twist in radians.

Can torsion bar springs be used for energy storage?

Yes, torsion bar springs can be used for energy storage. They store mechanical energy when twisted and can release this energy when they return to their original position. This characteristic makes them suitable for applications requiring energy absorption or the release of stored energy, such as in automotive suspension systems or mechanical watches.