Food cost is the amount of money it costs to acquire the food. Most operators include the cost of paper (packaging materials, boxes, etc) as “food cost”. Food cost percentage is the amount of money to acquire food divided by the net sales (gross receipts minus taxes). This number is more improtant that food cost because it gives you, the operator, a key indicator as to the amount of gross profit your store is making. In pizza, food costs of 25-35% are typical for overall sales. You will, of course, still have items which are far below, or far above those percentages, but it should average about 25-35% overall.
To figure your gross profit, calculate your net sales (usually one week periods work best), calculate your food cost and obtain your food cost percentage, and calculate your labor cost and obtain your labor cost percentage. Add the labor cost percentage together with the food cost percentage and if it is below 100%, you are making GROSS profit. If it is above 100%, you are either a start-up shop, having a really steep promotion, wasting too much food, mismanaging labor, or undercharging for your products. Food cost percent plus labor cost percent will typically range in the 40% (for a really lean company) to 70% (for the average company whose operator is not working shifts instead of his employees).
Tracking percentages on a weekly basis is helpful for determining problems occurring in the restaurant, i.e. theft, wastage, over-topping, etc. When you see the food cost percentage continually increasing over a several month period of time, it is time to increase your prices, find ways of reducing food costs (e.g. price negotations with vendors), or change vendors because food is getting too expensive.