Density Altitude Calculator

Enter pressure altitude and temperature to compare outside air temperature with a simplified ISA reference.

Enter pressure altitude from 0 to 20,000 ft and outside air temperature from −60 to 60 °C.

ISA_°C ≈ 15 − 2 × PA_ft / 1000; DA_ft ≈ PA_ft + 120 × (OAT_°C − ISA_°C)

ISA temperature ≈ 15 − 2 × (PA / 1,000) °C; DA ≈ PA + 120 × (OAT − ISA temperature) ft. This teaching rule uses a typical tropospheric range and a rounded 2 °C per 1,000 ft lapse rate. The accepted temperature bounds are input limits, not a guarantee of approximation accuracy at extremes. Humidity, aircraft characteristics and actual performance are not included. Do not use the result for flight decisions.

Reference: FAA Pilot’s Handbook of Aeronautical Knowledge