Density Altitude Calculator
Compute density altitude from field elevation, altimeter setting and temperature — the single number that tells you how your aircraft will really perform today.
Density altitude is pressure altitude corrected for non-standard temperature. Hot, high and humid days raise it — your aircraft performs as if it were at this altitude.
Formula
⚠️ For flight planning and education only — always verify against your aircraft's POH/AFM, official weather sources and certified instruments. Not for primary navigation or airworthiness decisions.
Compute density altitude from field elevation, altimeter setting and temperature — the single number that tells you how your aircraft will really perform today.
About Density Altitude Calculator
Density altitude is the most important performance number a pilot computes before takeoff on a warm day. This calculator turns field elevation, the current altimeter setting and outside air temperature into pressure altitude, ISA deviation and density altitude — instantly and entirely in your browser. The default scenario (a 30 °C afternoon at Centennial Airport near Denver) shows how a 5,434 ft field can behave like an 8,000+ ft one.
How to use Density Altitude Calculator
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula PA = elev + (29.92 − altimeter) × 1000; DA = PA + 118.8 × (OAT − ISA) substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Density Altitude Calculator?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula PA = elev + (29.92 − altimeter) × 1000; DA = PA + 118.8 × (OAT − ISA) with sources cited on the page
- ✓Density altitude is pressure altitude corrected for non-standard temperature. Hot, high and humid days raise it — your aircraft performs as if it were at this altitude.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What exactly is density altitude?+
Density altitude is pressure altitude corrected for non-standard temperature — the altitude in the standard atmosphere at which air density equals today's actual density. Engines, propellers and wings all respond to air density, so the aircraft performs as if it were physically at the density altitude, not the field elevation.
Why does high density altitude hurt performance?+
Thin air does three things at once: the engine produces less power (less oxygen per intake stroke), the propeller generates less thrust, and the wings need a higher true airspeed to make the same lift. The combined result is a longer takeoff roll and a noticeably weaker climb rate.
What counts as a 'high' density altitude?+
There is no regulatory limit, but many instructors treat anything above roughly 5,000 ft as a flag to recompute takeoff and climb performance from the POH, and 8,000 ft or more as territory demanding deliberate mitigation — reduced weight, an early-morning departure or a longer runway.
Does humidity change density altitude?+
Yes, slightly — water vapor is lighter than dry air, so humid air is less dense. The standard formula here ignores humidity, which can understate DA by a few hundred feet on muggy days. Use our METAR-based variant with dew point if you want the humidity-corrected figure.
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