# How do you calculate atmospheric pressure at an altitude?

##### 1 Answer

Atmospheric pressure is the force per unit area exerted on a surface by the air above that surface. As altitude increases, the mass of the atmosphere decreases, reducing the atmospheric pressure. The SI derived unit for pressure is the pascal (Pa). The standard atmospheric pressure at sea level is 101325 Pa. One atmosphere (atm) equals 101325 Pa.The formula used to calculate atmospheric pressure at an altitude is

where p = air pressure (Pa) and h = altitude above sea level in meters (m)

(Source: http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html)

**Example - Air pressure at Elevation 10000 m**

The air pressure at altitude 10000.0 m can be calculated as

=

Source: http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html)