To use a food cost calculator such as the one found on Free Online Calculator Use's website, first enter the menu item and its price. Enter each ingredient in the dish in column one, and input the lowest possible price to buy in bulk in column two. Column three is reserved for the number of units in the bulk purchase, and column four calculates the price per unit. Column five breaks shows the parts, or pounds, per unit.
Column six calculates the price per parts or pounds. Column seven prices the pieces per part; for example, if measuring one pound, the part number is 16, as there are 16 ounces in a pound. Column eight calculates the price for each piece, and column nine shows how many pieces are to be used in each serving. Column 10 calculates the total cost per serving of that ingredient. Complete this process for each ingredient in the meal.
Once all values are entered, click the button labeled Menu Item Food Cost Percentage Report. The portion size and cost of every ingredient are computed. The calculator displays an appropriate menu price for the item, as well as the total food cost and food cost percentage yielded for the meal.