Prime cost is the single most useful number in restaurant finance. These answers explain what it is, the target to aim for, and how to bring it down without hurting the guest. Primary source: U.S. Small Business Administration.
Prime cost is the sum of your cost of goods sold (CoGS, the cost of all food and beverage) and your total labor cost, including hourly wages, salaries, payroll taxes, and benefits. It captures the two largest and most controllable expenses in one figure. Prime cost is expressed as a dollar amount and, more usefully, as a percentage of sales. Because rent and other overhead are relatively fixed in the short term, prime cost is where most operators focus their day-to-day cost control.
A widely used rule of thumb is to keep prime cost at or below about 60 percent of total sales, with full-service restaurants often targeting near that figure and quick-service concepts sometimes running lower. Treat 60 percent as an industry benchmark, not an official standard, since the right target varies by format, region, and menu. What matters most is tracking your own prime cost over time and reacting quickly when it trends upward, rather than hitting one universal number.
Add your cost of goods sold to your total labor cost for a period, then divide by total sales for the same period and multiply by 100. For example, 300,000 dollars in CoGS plus 280,000 dollars in labor is 580,000 dollars; divided by 1,000,000 dollars in sales, that is a prime cost of 58 percent. Use accurate inventory counts for CoGS and full labor costs, including payroll taxes and benefits, so the number is not artificially low.
Food cost tells you only half the story. A kitchen can hit a great food-cost percentage while overspending badly on labor, or vice versa, so either number in isolation can hide a problem. Prime cost combines both into the figure that most directly determines whether there is anything left for rent, utilities, and profit. Watching prime cost weekly, rather than only reviewing food cost or a monthly P&L, gives operators the earliest reliable signal that costs are drifting.
Attack both halves. On CoGS: standardize recipes and portions, reduce waste and spoilage, renegotiate supplier pricing, and use menu engineering to promote high-margin items. On labor: schedule to forecasted demand, trim overtime caused by poor scheduling, and cross-train staff for flexibility. Do it without gutting quality or service, because cuts that slow tickets or shrink portions can reduce the sales the margin depends on. Small, sustained improvements on both sides compound quickly in a thin-margin business.
Weekly is the standard best practice for operators who actively manage costs. A monthly profit-and-loss statement arrives too late to correct a bad trend within the period, whereas a weekly prime-cost check lets you adjust ordering, portioning, and scheduling before the damage compounds. Weekly tracking requires disciplined weekly inventory counts and accurate labor reporting, but it turns prime cost from a backward-looking accounting figure into a real-time management tool.