Calculate Air Pressure at Altitude
Calculator for the expected air pressure at a target altitude based on the current values. Enter the current air pressure, altitude and temperature, as well as the target altitude and the temperature there. Target altitude pressure is an estimate for normal weather conditions, not for extremes. A less accurate but simpler calculation can be made using the international height formula.
The temperature gradient indicates how quickly the temperature falls with altitude. A good guess in normal weather is 0.0065 °C/meter.
Temperature gradient = ( Temperature at current altitude - Temperature at target altitude ) / Altitude difference
Barometric formula:
Atmospheric pressure at target altitude = Atmospheric pressure at current altitude * (1-temperature gradient*altitude difference/temperature at current altitude in kelvins)^(0.03416/temperature gradient)
Air pressure is the pressure that the earth's atmosphere has at a certain point. Objects in which there is a higher pressure, such as an inflated tire, push outwards. The SI unit for pressure is Pascal, air pressure is usually given in hectopascals (hPa), i.e. 100 Pascals. Millibars (mbar), i.e. a thousandth of a bar, are also used sometimes; this is the same as the hectopascal. Therefore, one bar corresponds to one hundred thousand Pascals. The unit atmospheres (atm) is occasionally used. 1 atm is the standard pressure at sea level, which is 1013.25 hPa. So converting this in your head is difficult and prone to errors. The pressure of 1013.25 hPa is part of the normal physical conditions.
Air pressure tends to fall with increasing altitude. Barometers are often calibrated so that they do not display the air pressure at the altitude at which you are, but the corresponding air pressure at sea level. For example, the actual air pressure at an altitude of 1000 meters is around 900 hPa, even if this indicates normal pressure on a calibrated barometer. At sea level, however, 900 hPa would be an extreme, hurricane-like low-pressure area.
Physics commonly uses SI units. Here is a calculator to convert lengths, temperature, pressure, speed and other units.
