Density and pressure altitude calculator

Pressure altitude is the standard-atmosphere altitude corresponding to station pressure. Density altitude is the standard-atmosphere altitude corresponding to the calculated air density. The model uses sea-level 101325 Pa and 288.15 K, lapse rate 0.0065 K/m, dry-air constant 287.05287 J/(kg·K) and gravity 9.80665 m/s². Moist density sums dry-air and water-vapour partial densities; warmer or more humid air generally increases density altitude.

Enter actual absolute pressure at the site. A weather report’s sea-level pressure or aircraft altimeter setting is not station pressure and must not be substituted directly.

Reference: NWS density altitude · Reference: standard atmosphere tables

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Atmosphere calculation

Density altitude from conditions

Absolute station pressure

1013.25 hPa

Air temperature

15 °C

Relative humidity

0 %

Primary result: Density altitude: 0 m.

• Check the selected mode, units and input values before using the result.
• Read the assumptions and rounding rules; compare the worked example with your intended calculation.
• A numerical result does not supply missing context or change the stated limitations.

This tropospheric educational model is limited to standard altitudes from −2000 to 11000 m. Density inputs allow −50–50°C for dry air, or −30–50°C when humidity is nonzero. Vapour pressure uses a liquid-water approximation. It is not an aircraft performance calculation; use the aircraft’s approved performance data and current operating conditions for flight decisions.