Air Pressure at Altitude Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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Atmospheric variables are coupled: temperature, pressure, humidity, and altitude can change together. Air Pressure at Altitude Calculator focuses on the specific relationship behind the displayed air pressure at altitude, helping you compare scenarios without implying a full weather or atmospheric model.

What this calculator does

The Air Pressure at Altitude Calculator uses Altitude above sea level, Sea-level pressure, Air temperature to estimate the page’s Air pressure at altitude from the atmospheric relationship below. It gives a focused engineering/meteorological estimate from the values you supply rather than attempting to simulate the full atmosphere.

How to use it

Start with the fields that actually drive this result: Altitude above sea level, Sea-level pressure, Air temperature. Keep units consistent with the menus beside the fields and avoid mixing values measured under different conditions. After calculating, change one input at a time if you are comparing scenarios; that makes cause-and-effect much easier to see.

How the calculation works

The page uses an isothermal barometric approximation p = p0·exp(−gMh/(RT)), with entered sea-level pressure and air temperature controlling the pressure decay with altitude.

Example

Using the page’s default example (Altitude above sea level = 1000 m; Sea-level pressure = 101325 Pa; Air temperature = 15 °C), the calculator reports Air pressure at altitude of 89,996.857448 Pa. Change one driving input at a time and confirm the result moves in the direction predicted by the equation; that is a quick way to catch a unit or mode mistake.

How to interpret the result

Interpret the Air pressure at altitude as an estimate for the entered atmospheric state and the approximation described above. It is useful for engineering checks and scenario comparisons, but it should not be read as a complete forecast or substitute for measured/local atmospheric data.

Limitations and notes

The isothermal barometric approximation holds temperature constant with altitude. The real atmosphere has lapse rates, weather systems, humidity, and nonstandard temperature profiles, so precision decreases as conditions depart from the assumptions.