The formula for hoop stress is the internal pressure times the internal diameter of the cylinder, divided by twice the wall thickness of the cylinder. The formula is expressed as ?h = (pd)/(2t), where ?h is the hoop stress, p is pressure, d is diameter and t is thickness.
The formula for the type of hoop stress exerted on the circumference of the cylinder wall is the force exerted divided by the product of the radial thickness and axial length of the cylinder. This formula is expressed mathematically as ? = F/(tl). The type of hoop stress measuring wall tension is calculated as the force over the axial length.