Example 1:

You are flying at 20000 ft and your altimeter is set to 29.92 inHg so that you are currently flying at a pressure altitude of 20000 ft or FL200. What is the indicated (or calibrated) altitude if you were to enter the local altimeter setting of 28.76 inHg?

Begin by highlighting the field that corresponds to pressure altitude in ft.

Enter the 20000 value.

Now highlight the field that corresponds to the altimeter setting in inHg.

Enter the 28.76 value.

The remaining field is the calibrated altitude one. Press "Eval" and read the answer 18909 ft on (a). You also get a result in meters in (b).

Example 2:

What is the pressure altitude if the altimeter indicates 8000 ft and is set to 29.50 inHg?:

Begin by highlighting the field that corresponds to calibrated (or indicated) altitude in ft.


Enter the 8000 value.

Now highlight the field that corresponds to the altimeter setting in inHg.

Enter the 29.50 value.

The remaining field is the pressure altitude one. Press "Eval" and read the answer 8392 ft on (a). You also get a result in meters in (b).