Near-instant and location accurate Density Altitude calculator/instrument app for iPhone and iPad that also finds relative air density (RAD), altimeter setting, relative humidity, specific humidity (grains/lb) and more. Super useful for pilots, especially in the backcountry. Many other uses for engine tuning, racing, sports, etc.

* Seamlessly integrates weather data, GPS and your phone's onboard barometer to quickly and accurately calculate your density altitude, altimeter setting, relative air density, and more.

* Takes humidity into account in all calculations, making it more accurate than the typical dry bulb approximation formula used by AWOS/ASOS, etc.

* Works anywhere. Great without cellular connection as well, which makes it all the more useful in the backcountry and far away from ASOS/AWOS stations.

Data Sensed and Calculated (all calculated with humidity):

* Density Altitude
* GPS Altitude
* Temperature
* Altimeter Setting
* Absolute Pressure
* Dew Point
* Relative Humidity
* Specific Humidity (grains/pound)
* Air Density
* Relative Air Density (RAD)
* Dyno Correction

The quickest way to get your Density Altitude! On the iPhone 6/6+ and newer iPads, it will use the built-in barometer and GPS. If you're in cell range, you don't need to supply any data. If you're out of cell range, all you need to supply is the outside air temperature. Designed not to need an internet connection, so it will work anytime and anywhere you need it.

Great tool for pilots, drag racers, engine tuners, golfers, or anyone who needs to conveniently find their Density Altitude, Altimeter Setting, Relative Aid Density (RAD), Specific Humidity or Absolute Pressure.

No ads or in-app purchases.

We love feedback! Email us at

What’s New

Version 2.1

- This version adds more calculated data helpful for racers and engine tuners:
- Specific Air Density in grains per pound of dry air
- Dyno Correction
- Now has a scroll view to fit more data onto small screens
Thanks for the great feedback! Email us anytime at

Ratings and Reviews

4.8 out of 5
376 Ratings

376 Ratings

Farabaugh ,

Works well

Wanted something to quickly calculate DA so I could input into my ballistics shooting app. I know this is designed for pilots but I thought it worth the try. Non humid days, works well. High humidity it’s off. I know this app uses dry air formula so not knocking the app. Developer did mention other possible uses tho.
To be able to manually enter values by turning off an automatic fill button would be great.

DA is becoming a more widely used method on ballistic applications over the previous idea of entering elevation and temperatures.

RF219 ,

Great app

I really like this app. It works pretty good against my kestrel hand held weather station. I would like to see a tab for water grains in the air for the guys using it for drag racing

Developer Response ,

Thanks for the feedback! Good idea! I've added water grains now as well as Dyno Correction. It's in the 2.1 update. Thanks!

N801bz ,


Quick and location accurate. A must for Mtn flying.


Kristian Ljungkvist
20 MB

Requires iOS 10.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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