I was taught to fly in meters above ground and do a mental conversion
by multiplying the meters by three and adding 4 500ft to get the real
altitude when speaking to the ATC. I then bought a glider without a
meter altimeter - only a ft one which is set to show altitude above sea
level. No more problem when speaking to ATC but found I was doing
reverse calculations to find out how high I was above the hard stuff.
Then I set my palm up with Soaringpilot which now has a digital terrain
model built in. Now I know exactly how high I am above the ground -
even when I fly cross-country in the mountain regions not far from my
airfield. My LX 5000 computer is set up to show my height above my home
field, which is more important for final glide than anything else.

Clinton Birch
LAK 12