Cooked serving size

Hi,

I have just started bare lean and am cooking for myself, husband and two kids. I am multiplying the recipes to accomodate for all of us and also to be economical using whole cans of food, mince in 500g quantities.

Is there anyway to know the recommended cooked serving size? Eg I have made a big batch of baked beans for my family for the week breakfasts, how much would I serve myself each morning? Do I just weigh out the same amount as the primary ingredient in the dish so for this dish would be the beans- for which my guide says 180g canned butter beans.