In physics, a unit of pressure equal to 760 torr, 1013.25 millibars, or 1.01325 x 10⁵ newtons per square meter (the terms used here are located in this unit).

The actual pressure exerted by he atmosphere fluctuates around this value, which is assumed to be standard at sea level and zero degrees centigrade/32 degrees Fahrenheit, and is used when dealing with very high pressures.