Density Altitude Calculator – from Pressure Altitude & Temperature

Quickly calculate density altitude using pressure altitude and temperature.

Density Altitude Calculator

What is Density Altitude

Density Altitude is the altitude at which the air density corresponds to standard atmospheric conditions (International Standard Atmosphere – ISA) for a given pressure and temperature. Formally, it is defined as “pressure altitude corrected for nonstandard temperature variations.”

Why Density Altitude Matters

  • High density altitude: Air is less dense → reduced engine power, reduced lift, longer takeoff and landing distances.
  • Low density altitude: Air is denser → improved aircraft performance.
  • Pilots must consider density altitude at high-altitude airports, hot days, or high humidity conditions.

How It’s Calculated

The calculator uses the standard aviation approximation:

Density Altitude Formula:
DA (ft) = Pressure Altitude (ft) + 118.8 × (OAT (°C) − ISA Temp (°C))

Where:

  • ISA Temp (°C) = 15 − 2 × (Pressure Altitude in 1000 ft)
  • OAT (°C) = Actual outside air temperature
  • 118.8 factor = Converts the temperature deviation to feet of density altitude

Interpretation:

  • OAT > ISA → density altitude higher than pressure altitude → decreased performance
  • OAT < ISA → density altitude lower → increased performance

Using the Calculator

  1. Enter Pressure Altitude (ft).
  2. Enter Temperature and select unit (°C or °F).
  3. The calculator outputs:
    • Density Altitude (ft)
    • ISA Temperature at that altitude (°C)
    • Temperature deviation (°C)
  4. Displays a warning if density altitude exceeds 8000 ft, indicating potential performance reduction.