Converting Pounds Per Square Inch or PSI to Atmospheres

Worked Pressure Unit Conversion Problem

Need to fill up your bicycle tires? It's helpful to know how to convert between PSI and atm!
Need to fill up your bicycle tires? It's helpful to know how to convert between PSI and atm!. Susanna Price, Getty Images

This example problem demonstrates how to convert the pressure unit pounds per square inch (psi) to atmospheres (atm).

PSI to Atm Problem

A bicycle tire is inflated to 65 psi. What is this pressure in atmospheres?

Solution:

1 atm = 14.696 psi

Set up the conversion so the desired unit will be canceled out. In this case, we want atm to be the remaining unit.

pressure in atm = (pressure in psi) x (1 atm/14.696 psi)
pressure in atm = (65/14.696) atm
pressure in atm = 4.423 atm

Answer:

The average sea level air pressure is 4.423 atm.