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
What Is PSI? Definition of Unit
![Close-up of the meter on a pressure gauge](https://cdn.statically.io/img/www.thoughtco.com/thmb/eM3b0pKQ7uHjZevv-kO8CCOgzzM=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/GettyImages-114251748-a3a6bd2b6d23486c831b48a9cc0f3b38.jpg)
crescott / Getty Images
crescott / Getty Images
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