This scale is used to rate the attractiveness of a woman. Basically the better looking the woman the more undercooked burgers we would give her and hence she would get terrible diarrhea that we would smear all over ourselves and eat. Slightly attractive girls would get 1 or 2 burgers. Whereas really hot girls might get up to 4 or 5 burgers.
"Holy shit, did you see her? if I use The burger scale she would have gotten 5 burgers."
Sam: "How many burgers would you give kitty?"
Jimbop:"Well if i was using the trusty burger scale i would probably only give her about 2 burgers. shes no brad pitt."