Air Pressure at Altitude Calculator

Estimate barometric pressure (hPa) at altitude

Default is standard sea-level pressure (1013.25 hPa).

How to Use This Calculator

1

Enter Altitude

Provide height above sea level in meters.

2

Sea-level Pressure

Use default 1013.25 hPa, or enter current sea-level pressure.

3

Calculate

Result shows estimated pressure at the given altitude.

Formula

p = p₀ · (1 − L·h/T₀)^(g·M/(R·L))

Where: p₀ = sea-level pressure, h = altitude, L = 0.0065 K/m, T₀ = 288.15 K, g = 9.80665 m/s², M = 0.0289644 kg/mol, R = 8.3144598 J/(mol·K)

Note: Valid in the troposphere (up to ~11 km) assuming standard lapse rate.

About Air Pressure vs Altitude

Atmospheric pressure decreases with altitude because the weight of the air column above decreases. Weather patterns also shift surface pressure from the standard value.

Applications

  • Aviation: Understanding density altitude and performance
  • Meteorology: Converting station pressure to sea-level pressure
  • Hiking: Estimating weather impacts at elevation

Frequently Asked Questions

Why does pressure drop with altitude?

There is less air above you exerting weight, so the pressure is lower.

Is temperature considered?

Yes, the standard lapse rate (L) models how temperature decreases with height.