🏔️ Air Pressure at Altitude Calculator
Estimate atmospheric pressure at a given altitude above sea level using the standard barometric formula.
m
hPa
°C
What this calculates
Atmospheric pressure decreases as altitude increases because there is less air above pushing down. This calculator uses the barometric formula from the International Standard Atmosphere model to estimate pressure at a given height.
The formula
For the troposphere, P = P0 × (1 – L·h / T0)^(g·M / (R·L)), where L = 0.0065 K/m is the standard temperature lapse rate, g = 9.80665 m/s², M = 0.0289644 kg/mol (molar mass of air), R = 8.3144598 J/(mol·K), h is altitude, and T0 is sea-level absolute temperature.
This gives a standard-atmosphere estimate; actual local pressure varies with weather conditions.
Last reviewed August 2026