PA = (29.92 − altimeter) × 1000 + field elevation
DA = PA + (120 × (OAT°C − 15.0)) + (0.0034 × PA × (OAT°C − 15.0)²) (refined)
Pilots and drone operators know that hot days at mountain fields can turn a runway into a “long” one. Density altitude is your aircraft's true performance altitude. It combines the effects of pressure (pressure altitude) and temperature. When density altitude is high, air is thin, which robs wings of lift and engines of power. This calculator gives you a quick read — no apps, just your field elevation, altimeter setting, and temperature.
The pressure altitude calculator portion uses the standard altimeter of 29.92 inHg. For every 0.01 inHg difference from standard, your field elevation shifts by roughly 10 feet. Then, we add the non-standard temperature effect: the density altitude formula multiplies the difference from standard temperature (15°C) by 120 feet per degree Celsius, plus a quadratic term for hot-day accuracy — a refined method often used in aviation textbooks.
If you're flying RC, paragliding, or preflighting an aircraft, check both values. Comparing pressure altitude and density altitude tells you how much the heat is “adding” altitude. Use it to estimate climb performance and ground roll. For quick calculations, bookmark this tool and enter current weather. No backend — everything is computed locally in your browser.
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