Plan on 1 1/2 potatoes per a person. This depends on how close you want to cut it. If it is important that you don't run out go to 2 potatoes a person. If some of the people are younger or older and can't eat as much this should be taken into account and provide about a half a potato. This estimation is based on a regular sized russet or bakers potato.
That is 87.5 pounds
To serve 300 people, you will need about 9.375 gallons of potato salad. This is based on one gallon being 16 cups, so, if you figure 1/2 cup per serving, one gallon should serve 32 people.
25 pounds of potatos shoud be about right.
Since 25 pounds feeds 100, you'll need 106 1/4 pounds of potato salad.
2.5 pounds of potato
5 lbs would make enough for about 20 people. Glad I could help.
The normal serving of potato salad should be around 4 ounces. 1 pound would feed 4 people, so you would need 33 and 3/4 pounds to feed 135 people.
I would serve 4 oz per person. So 5 pounds for 20 people.
potatos
I would get 20 pounds.
Four ounces is considered the normal serving. For 150 to 200 people you will need 40 to 50 pounds. If they are hungry you may want to go more than that!
A good rule of thumb with any potato dish is 1 potato per person. This always works because some will eat less.