For steels up to 100,000 psi ultimate tensile strength

F_{total = σ allow} * A_total

A_total=A_t * N_b

F_total: Total Force (pound)
A_total: Total Tensile Stress Area (inch²)
A_t: Tensile Stress Area Per Bolt (inch²)
D: Basic Major Diameter (inch)
n: Threads Per Inch
σ _allow: Allowable Stress (pound / inch²)
N_b: Number of Bolts