Pounds-force per Square Inch (PSI) is a non-SI unit of pressure.
For technical accuracy, pressure must be expressed as psig (pounds-force per square inch gauge) or psia (pounds-force per square inch absolute; that is, gauge pressure plus sea level atmospheric pressure, or psig plus approximately 14.7 pounds per square inch). Also see torr which is a measurement of millimeters of Mercury, and pascals which is the SI unit.
- 1 psi approximately equals 6.895 kPa
