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.
Chemistry Expert
  • Ph.D., Biomedical Sciences, University of Tennessee at Knoxville
  • B.A., Physics and Mathematics, Hastings College
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.
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Anne Marie Helmenstine, Ph.D.
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.