How much food do I need?

Ohhhhh.... I need to know this as well... my guest list is around 150 too.... bump for my knowledge!

I would estimate 1/2 lb. meat per person. Do 1/2 of the total as brisket, and 1/4 of the total meat for chicken and sausage. So 75 lbs total, 37.5 or so for brisket about 7.5 minimum each sausage and chicken. I'd round those up to nice even numbers, no harm in having left overs. Figure 1-2 cups each person for sides.

@Michelle S. THANK YOU SO MUCH!!

For foods that can be cooked in quantity, it's always good to have extra... so measure out (for example) 1/2 cup of rice per guest, 1/4 cup beans per guest, 1/2 cup potato salad per guest (potato salad is usually popular enough that people want seconds)... as for meat? I recommend 1 sausage, a thigh of chicken (about), and 3 ounces of brisket per person... I know that sounds like a lot of food, but imagine that some people might want extra of one and none of another.

Michelle's estimate is exactly what I would have said (math is off 17-18 pounds of chicken and sausage)... Now, if the chicken is bone in, you may want to go a little higher to offset the bone weight.

Are you doing foil pans or roasters? sausage links are cut up to bite size? chicken,bone in or boneless?.....chicken you would go by piece not by wieght...and depending how your serving the sausage it could go by weight or piece..say for example if you get a case of link sausage from sam's club 2 case will be enough with some left over,cut it up into bite size pieces add some colored peppers onions and some diced tomatoes you'll be good...a large foil pan of salad will usually feed 25-30 people...brisket do like 6 oz per person....beans 3 large foil pans and same for the beans and rice...potato salad you might want to do 4 pans.