Barlow’s Formula Calculator

Barlow’s Formula is an equation which shows the relationship of internal pressure, allowable stress, nominal thickness and diameter. You can use Trident Steel’s calculator tool to determine bursting pressure of line pipe.


      P = ID pressure (psi)
      T = Wall thickness (in)
      OD = Outside Diameter (in) *Must be a decimal*
      SF = Safety factor (generally 1.5 – 10, 1 for collapsing pressure)
      S = Material strength (psi) *Minimum yield strength*
OD (in)      (in)
Wall (in)      (in)
Strength Factor (minimum yield strength)      (psi)
Safety Factor (working)
Safety Factor (bursting) 1
Theoretical Working
(selected SF)
Theoretical Bursting or
Yeilding Pressure
*Disclaimer: Formulaic calculators are provided purely for illustrative purposes, and should not be relied upon for any technical, engineering, or application-specific purpose. For technical information, consult a licensed petroleum engineer.