Calculating Density Alttitude of Air knoing temp/baro/humidity?

• soundengineer
In summary, the conversation discusses using a calculator to calculate the Density Altitude of air using known data such as temperature, barometric pressure, and humidity. The conversation also mentions the need for a formula rather than a calculator, and the possibility of using spreadsheets or reports to perform the calculation.
soundengineer
I'm trying to figure out the Density Altitude of Air
Known data
Temp 70*F
Barometric Pressure 30inHg
Humidity 35%

do I need more data or can I calculet it from this?

There are many calculators available to do this. One is at:
http://www.srh.noaa.gov/epz/wxcalc/wxcalc.shtml
With this one you need to calculate Dewpoint temp first using the first moisture calculator then calculate the density altitude.
BTW humidity when it is in a % is relative humidity.

Last edited by a moderator:
nucleus said:
There are many calculators available to do this. One is at:
http://www.srh.noaa.gov/epz/wxcalc/wxcalc.shtml
With this one you need to calculate Dewpoint temp first using the first moisture calculator then calculate the density altitude.
BTW humidity when it is in a % is relative humidity.

I need an actual formula...not a calculator
calculator doesn't do me any good in an excel spreadsheet...

so what's the formula for dewpoint with known temperature and relative humidity
and then once I have dewpoint how do I get to Density Altitude?

Last edited by a moderator:
The formulas are on the site I gave you. There are also spreadsheets on the net that do what you want to do.
As for Td some reports already include it.

1. How do I calculate density altitude of air knowing temperature, barometric pressure, and humidity?

To calculate density altitude, you can use the following formula: Density Altitude = [Pressure altitude + (120 x (OAT - ISA Temp))] + [0.002 x (Barometric pressure - 29.92)]

2. What is the significance of calculating density altitude in air?

Density altitude is important for aircraft performance calculations as it directly affects the amount of lift and thrust an aircraft can generate. It is also used in determining aircraft takeoff and landing distances, as well as engine power output.

3. How does humidity affect density altitude?

Humidity, or the amount of water vapor in the air, affects density altitude by decreasing air density. This is because water vapor is less dense than dry air, so the more humid the air is, the less dense it becomes. This in turn, increases the density altitude.

4. What are the units used for density altitude?

Density altitude is typically measured in feet or meters, depending on the standard unit of measurement in a particular country or region. In aviation, it is most commonly measured in feet.

5. Are there any tools or resources available for calculating density altitude?

Yes, there are various online calculators and apps available for calculating density altitude based on temperature, barometric pressure, and humidity. Some aviation weather apps also have a feature for calculating density altitude.

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