Wowzers?? Well if it feels comfortable then it's the right size
But on a serious note as frame geometry varies so does the suitability of frame, I'm a tad over 6ft, 33" leg and fairly long reach, and in my collection have 18" Frame, 19" Frame, some sized as Large, one Full Susser in a Medium, I'm sure if you took all the measurements they would all vary slightly, some more than others, however all are comfortable as they are set up for me and my riding style, some have riser bars some flats some have Front rigid forks others with anything between 60mm & 100mm of Suspension Fork travel. You can roughly size against inside leg, reach and height but there are some tall riders who prefer smaller frames than to be sat on a Gate. If you can try before you buy then its a bonus but if you are doing a build from scratch then it may be a case of trial and error until you get that comfortable ride
"Would anyone else rather be doing something other than marching up and down the square????"