How do you calculate density altitude?

Start with pressure altitude: field elevation plus (29.92 minus the altimeter setting) times 1,000. Then correct for temperature: add about 120 ft for every degree Celsius above standard temperature at that altitude, or subtract for every degree below. Standard temperature is 15°C at sea level and drops about 2°C per 1,000 ft.

What does high density altitude do to a drone?

Thinner air means each propeller revolution moves less air, so the drone has less thrust in reserve. Expect a slower climb, less margin to hold position in gusts, and shorter battery life. The manufacturer's limits, not a calculator, say how much performance is left.

What raises density altitude?

High temperature, high field elevation and high humidity. All three make the air less dense, and all three reduce performance.

Is density altitude on the Part 107 test?

Yes. Weather and loading and performance questions ask how temperature, elevation and humidity change density altitude and how that affects aircraft performance.

Density altitude calculator

What is the density altitude right now?

Pick an airport, a city, or your location. The calculator pulls the latest METAR, works out pressure and density altitude, shows the exam method step by step, and tells you what the air is doing to your drone's performance.

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Conditions (edit any value to plan a different time or site)

Field elevation (ft MSL)

Altimeter setting (inHg)

Temperature (°C)

Dew point (°C, optional)

Density altitude

6,687 ft

Thinner than the field elevation suggests · 1,253 ft above the field

Propellers move less air per revolution. Climb and hover margins shrink, and the motors work harder for the same flight.

Pressure altitude

5,434 ft

Standard (ISA) temperature there

4.2°C

Air density vs sea-level standard

82%

Relative humidity

Not given (dry air)

How the exam method gets there

1. Pressure altitude = field elevation + (29.92 − altimeter) × 1,000
= 5,434 + (29.92 − 29.92) × 1,000 = 5,434 ft
2. Standard temperature at that altitude = 15°C − 2°C per 1,000 ft ≈ 4.2°C. Today's 15.0°C is +10.8°C from standard.
3. Density altitude ≈ pressure altitude + 120 ft × +10.8°C = 6,725 ft

The headline figure (6,687 ft) is calculated from actual air density, so it also counts humidity, which the rule of thumb leaves out. The two usually land within a few hundred feet.

Hot

Warm air is less dense. Every degree above standard adds roughly 120 ft of density altitude.

High

Higher fields start with less air overhead, before temperature even enters the picture.

Humid

Water vapor is lighter than the air it displaces, so humid air is less dense than dry air.

Live data is the latest METAR from the NOAA Aviation Weather Center and can be up to an hour old. This is a study and planning aid, not a performance chart: your drone's limits come from the manufacturer. Background in density altitude and drone performance.

Density altitude questions

How do you calculate density altitude?: Start with pressure altitude: field elevation plus (29.92 minus the altimeter setting) times 1,000. Then correct for temperature: add about 120 ft for every degree Celsius above standard temperature at that altitude, or subtract for every degree below. Standard temperature is 15°C at sea level and drops about 2°C per 1,000 ft.
What does high density altitude do to a drone?: Thinner air means each propeller revolution moves less air, so the drone has less thrust in reserve. Expect a slower climb, less margin to hold position in gusts, and shorter battery life. The manufacturer's limits, not a calculator, say how much performance is left.
What raises density altitude?: High temperature, high field elevation and high humidity. All three make the air less dense, and all three reduce performance.
Is density altitude on the Part 107 test?: Yes. Weather and loading and performance questions ask how temperature, elevation and humidity change density altitude and how that affects aircraft performance.

Read more: density altitude and drone performance, how to read a METAR, and the METAR decoder with its Part 107 altitude check.