How this is calculated. Gross margin per serving is your retail price minus your food and packaging cost, multiplied by servings per day and by the operating days you entered. Expansion savings hold finished popcorn volume constant: the corn required on each kettle is inversely proportional to its measured expansion, and oil is scaled from each kettle’s oil-to-corn ratio. Cost per pound is derived from the purchase unit and price you entered. Default food costs are estimated from current wholesale supply pricing for a typical serving size and standard packaging; default retail prices reflect mid-range independent concession pricing. Your supplier costs and local prices will differ — edit any figure. Figures exclude labor, utilities, rent, waste, shrink, card fees, taxes, and equipment. Corn and oil move with the market, and expansion varies with corn variety, moisture, kettle temperature, and operating practice, so your results will differ from laboratory conditions. Estimates are for informational purposes only and are not a guaranteed return.