This is what the website says...
Size Head Angle Seat Angle Top Tube Head Tube Chain Stay Wheel Base Standover Height
S/46,5 72.0 74.0 53.0 14.5 42.0 99.0 75.4
M/50,0 72.5 73.5 54.5 16.5 42.0 99.5 77.7
M/L53,5 72.5 73.0 56.0 18.5 42.0 100.7 79.0
L/55,5 72.5 73.0 57.5 20.5 42.0 102.2 81.3
XL/58,5 72.5 72.5 59.5 22.5 42.0 103.7 83.3
If you click on my link you see it with better formatting.
I think Giant do it a bit different in terms of how they size bikes.
I'm 5'10" and it was right for me.
It is a M and not an M/L.
Thanks