Pressure Altitude Calculator
Understand altitude beyond the elevation on the chart.
Uses the standard 1,000 ft per inHg approximation. Enter the altimeter setting (QNH), not station pressure or QFE. Negative pressure altitudes are valid.
Formula, units & limitations
PA (ft) ≈ field elevation (ft) + (29.92 − altimeter setting inHg) × 1,000. 1 inHg = 33.8638866667 hPa; 1 ft = 0.3048 m. This is an approximation, not a full atmospheric model.
Supported inputs: altitude −2,000 to 30,000 ft (direct PA −5,000 to 30,000 ft); QNH 25–35 inHg; temperature and dew point −100 to 60 °C. These ranges bound this calculator, not aircraft operating limits.
For current airport weather, open official METAR observations. Weather values are entered manually.