A LOT! If you are making the potato salad why not look at pots in the shops as they generally contain serving proportions and how many they will serve or a average portion size on the nutritional information on the back. Or.. Get a friend and discover how much potato salad is consumed by two of you and then times this amount by 100! Some recipes also tell you how many people they will serve. If you are having caterers or cooks ask them as they are hopefully experienced in their field! GOOD LUCK!! And enjoy your potato salad- it is better to have too much rather than too little and you can always eat left overs another day!
