Barometric Pressure to Altitude Calculator – hPa to m/ft

The calculator applies the standard-atmosphere relation h = 44330 × (1 − (P/P₀)^0.1903), where P is the measured pressure and P₀ the sea-level reference (1013.25 hPa by default). Enter both in hectopascals — the same units a barometer or weather app shows — and the altitude appears in metres and feet, plus an air-density estimate that falls linearly with pressure. Because weather moves sea-level pressure by ±30 hPa, always enter the current QNH for survey-grade results.

1. 1

   Step 1

   Enter the measured pressure in hPa

2. 2

   Step 2

   Enter the sea-level reference (1013.25 for the standard atmosphere)

3. 3

   Step 3

   Read the altitude in metres and feet

4. 4

   Step 4

   Compare air density for drone and engine planning