✈️ Density Altitude Calculator
Enter your field elevation, altimeter setting and outside air temperature to get the pressure altitude and density altitude.
Density altitude
3,675 ft
Pressure altitude
2,000 ft
Density altitude is the altitude the air "feels like" to a wing or propeller — pressure altitude corrected for temperature. Pressure altitude = elevation + (29.92 − altimeter) × 1,000 ft; density altitude ≈ PA + 120 × (OAT − ISA temp), where the ISA temperature drops about 2 °C per 1,000 ft. High density altitude (hot, high, humid) reduces engine power, lift and climb. This is the standard pilot approximation — use official performance charts for flight planning. 🔒 In your browser.
How the density altitude calculator works
Pressure altitude is your elevation corrected for the current barometric pressure: PA = elevation + (29.92 − altimeter setting) × 1,000 ft. Density altitude then corrects that for temperature — the altitude the air actually performs like: DA ≈ PA + 120 × (OAT − ISA temperature), where the standard (ISA) temperature falls about 2 °C per 1,000 ft from 15 °C at sea level. Hot, high and humid conditions push density altitude well above your true altitude.
High density altitude thins the air, cutting engine power, propeller thrust, wing lift and climb performance — a leading factor in hot-and-high takeoff accidents. This is the standard pilot approximation (it ignores humidity, a smaller effect); use your aircraft's performance charts and official weather for actual flight planning.
Frequently asked questions
What is density altitude?
The altitude at which the air density equals what your aircraft is actually experiencing — pressure altitude corrected for temperature. On a hot day at a high-elevation airport, the density altitude can be thousands of feet above the field elevation.
How do you calculate density altitude?
First find pressure altitude: elevation + (29.92 − altimeter) × 1,000. Then density altitude ≈ PA + 120 × (outside air temp − ISA temp), where ISA temp = 15 − 2 × (PA/1,000) °C. The tool does both from your inputs.
Why does density altitude matter for flying?
Because thinner air reduces engine power, propeller efficiency, lift and climb rate, and lengthens the takeoff roll. High density altitude — hot, high, humid — is a common cause of poor takeoff performance, so pilots check it before departure.
What is pressure altitude?
Your altitude referenced to the standard pressure of 29.92 inHg (1013.25 hPa). Set 29.92 in the altimeter and it reads pressure altitude; the tool computes it from your field elevation and current altimeter setting.
Does humidity affect density altitude?
Yes, slightly — humid air is less dense, raising density altitude a little — but the standard pilot formula (used here) ignores it because the effect is small compared with temperature and pressure. For precise figures use a full atmospheric model.