I usually just keep it memorized what the average height and weight of a person is based on what their task is and what era it is.

ex: In Medieval times, human beings were about a foot shorter on average than they are today.

ex 2: Muscle weighs more than fat. So if you have a 180 pound character at about 5'11", but they're depicted in a role that is highly physically demanding (being a knight, a blacksmith, etc) then the extra weight is appropriate.

Then again, so long as it doesn't go off into outlandish bizarroland territory, I don't tend to mind much what weight and height people make their characters at. Especially if they're non-humans.