Calculate the density altitude for any airfield using your pressure altitude, temperature, and dew point. Enter your field elevation, altimeter setting, outside air temperature, and dew point — and get back the density altitude in feet and meters, helping you assess true aircraft performance conditions.
Density Altitude
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Density Altitude (Meters)
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Pressure Altitude
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ISA Temperature Deviation
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ISA Standard Temperature
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Virtual Temperature
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Density altitude is the pressure altitude corrected for non-standard temperature and humidity. It represents the altitude at which the air has a given density, and is used to determine how an aircraft will actually perform — the higher the density altitude, the thinner the air and the worse the performance.
Aircraft performance — including takeoff distance, climb rate, engine power, and propeller efficiency — is directly affected by air density. A high density altitude means the air is less dense, so the aircraft behaves as if it were at a higher elevation than it physically is, requiring longer runways and reducing climb performance.
Density altitude is computed by first finding pressure altitude (correcting field elevation for altimeter setting deviation from 29.92 inHg), then applying a temperature correction based on the deviation from the ISA (International Standard Atmosphere) standard temperature. Humidity (dew point) is factored in via virtual temperature to account for moist air being less dense than dry air.
Pressure altitude is the altitude indicated when the altimeter is set to 29.92 inHg (standard sea-level pressure). Density altitude builds on this by also correcting for temperature — hot, humid days make the air less dense, pushing density altitude higher than pressure altitude.
Higher temperatures cause air to expand and become less dense, increasing density altitude. On a hot summer day, a 5,000 ft airport can have a density altitude of 8,000 ft or more, significantly degrading aircraft performance. This is why hot-and-high conditions are considered especially hazardous.
Yes. Moist air is actually less dense than dry air at the same temperature and pressure, because water vapor (H₂O, molecular weight 18) displaces heavier nitrogen and oxygen molecules. High humidity increases density altitude, further reducing aircraft performance — especially significant in hot, humid climates.
ISA defines standard atmospheric conditions: 15°C and 29.92 inHg (1013.25 hPa) at sea level, with a temperature lapse rate of 2°C per 1,000 ft. Density altitude calculations compare actual conditions against this standard to determine how performance differs from the baseline.
Most light aircraft are significantly impacted above 5,000–6,000 ft density altitude. At 8,000 ft density altitude and above, performance degradation becomes severe — takeoff distances can double and climb rates can drop by 50% or more compared to sea-level standard conditions. Always check density altitude before operating at high-elevation airports or on hot days.