How do I figure out my height?

I send my Grandson up the ladder onto the roof with a tape measure. We measure the ground to the highest obstacle sticking up above the roof. Then I use a piece of scotch tape which is in the lower left corner of front windshield and write my overall height on the scotch tape with a magic marker. That way my height will always be there for trips later on down the road no forgetting "Write it don't say it". And remember all that changes with ice or snow on the road surface.