Converting Atmospheres to Pounds Per Square Inch (PSI)

Worked Pressure Unit Conversion Problem

psi pressure gauge

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by Anne Marie Helmenstine, Ph.D.
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
Updated May 07, 2019

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

Problem:
The pressure under the ocean increases roughly 0.1 atm per meter. At 1 km, the water pressure is 99.136 atmospheres. What is this pressure in pounds per square inch?

Solution:
1 atm = 14.696 psi

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

pressure in psi = (pressure in atm) x (14.696 psi/1 atm)
pressure in psi = (99.136 x 14.696) psi
pressure in psi = 1456.9 psi

Answer:
The pressure at a depth of 1 km is 1456.9 psi.