What Is PSI? Definition of Unit

Close-up of the meter on a pressure gauge

crescott / Getty Images

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.
our editorial process
Anne Marie Helmenstine, Ph.D.
Updated January 13, 2020

PSI definition: PSI is a unit of pressure expressed in pounds of force per square inch of area. It stands for Pounds per Square Inch.
1 PSI = 6894 Pascals = 0.070 atmospheres = 51.715 torr

Format
mla apa chicago
Your Citation
Helmenstine, Anne Marie, Ph.D. "What Is PSI? Definition of Unit." ThoughtCo, Aug. 29, 2020, thoughtco.com/what-does-psi-stand-for-605565. Helmenstine, Anne Marie, Ph.D. (2020, August 29). What Is PSI? Definition of Unit. Retrieved from https://www.thoughtco.com/what-does-psi-stand-for-605565 Helmenstine, Anne Marie, Ph.D. "What Is PSI? Definition of Unit." ThoughtCo. https://www.thoughtco.com/what-does-psi-stand-for-605565 (accessed May 18, 2021).