# Pressure

Pressure is defined as the force exerted per unit area. The SI unit of pressure is the pascal or newton per square metre.

Pressure is a similar idea to stress, the force intensity at a point, except that pressure means something acting on the surface of an object rather than within the material of the object. When discussing the pressure within a fluid, the meaning is equivalent to stress.

The pressure in a liquid increases with depth.

1 bar | = | 1x10^{5} Pa | 1 standard atmosphere (atm) | = | 1.01325x10^{5} Pa | |

1 lbf in^{-2} (psi) | = | 6894.76 Pa | 1 tonf in^{-2} | = | 15.4443x10^{6} Pa | |

1 torr | = | 1 mmHg | 1 mmHg | = | 133.322 Pa | |

1 inHg | = | 3386.39 Pa | 1 inH_{2}O | = | 249.089Pa | |

1 mmHg | = | 13.5951 mmH_{2}O | 1 mmH_{2}O | = | 9.8066 Pa | |

1 kilo psi | = | 1 ksi | 1 ksi | = | 1000 psi |

**See also: **Absolute Pressure, Acoustics, Atmospheric Pressure, bar, Barye, Burst Pressure, Centimetre of Mercury, Centimetre of Water, Differential Pressure Indicator, Dynamic Pressure, Gauge Pressure, Hydrostatic Pressure, Isobaric, Manometer, Negative Pressure, Pascal, Pressure Drop, Pressure Gauge, Pressure Gradient, Pressure Head, Rated Pressure, Standard Atmosphere, Static Pressure, Thermodynamic Properties, Vacuum, Working Pressure, Zero Absolute Pressure.

**Subjects: ** Aerodynamics Fluid Dynamics Mechanical Engineering Noise & Vibration Physics