Equation 3: Atmospheric Pressure
where:
| h | Height above the radius (m) |
| Ph | Pressure at height (h), in standard atmospheres |
| Po | Pressure at radius (r), in Pascals (Pa) |
| e | 2.718281828... (natural logarithm) |
| Mm | Molar mass of the atmosphere (kg) |
| Mp | Mass of the planet (kg) |
| T | Temperature of the planet at the planetary radius (K) |
| r | Planetary radius (m) |
Note:
Ph in Pascals (Pa) is obtained by using J=1
This is a simplified version of a very complex equation
This equation can also be used for depths (h < 0)
These calculations are available in a MS Excel format from here
Radius, Maximum and Mountain-top Atmospheric pressures
| Planet | Po | Pmax | Pmin | Heighest mountain |
| Earth | 1 | 1 | 0.3507 | Mount Everest |
| Venus | 91.17 | 102.268 | 44.7 | Mount Maxwell |
| Mars | 0.00691 | 0.00873 | 0.00085 | Mount Olympus |
"90 Earth atmospheres" is often quoted as an excuse for the poor habitability of Venus. So it's important to note: atmospheric pressure on the surface of Venus starts at 44.7 atmospheres, at the top of Mount Maxwell.