Tools / Density altitude

Density altitude

Pressure and density altitude from elevation, QNH and temperature.

Field elevation (ft)

QNH

QNH units

Outside air temperature (°C)

Pressure altitude = elevation + 145,366 × (1 − (QNH ÷ 1013.25)^0.1903). ISA temperature falls 1.98 °C per 1,000 ft from 15 °C. Density altitude ≈ pressure altitude + 118.8 × (OAT − ISA temperature). High density altitude means longer take-off runs and weaker climbs.

For flight simulation only. Always follow your aircraft's procedures and the published charts.