mined from this thread -

>>> I'm about the same size as E-Richie, and our saddles are 12cm lower than yours...
>>> 11 is right in the range for your size. That's why bigger frames should have
>>> shallower seat tube angles than small ones...

protractors are the tool of the devil and john schubert atmo.
lose them. go get a steel rule with millemeters. linear rules.