Prime cost is the sum of your food and beverage costs plus your total labor costs. It’s the single most important number for understanding whether your restaurant can actually make money.

The formula is straightforward. Cost of Goods Sold (what you pay for food and drinks) plus Labor (wages, payroll taxes, benefits) equals Prime Cost. Most restaurants express this as a percentage of total revenue. If you brought in $50,000 last week and your prime cost was $32,000, your prime cost percentage is 64%.

Why these two expenses specifically? They’re your largest controllable costs. Rent is fixed. Insurance is fixed. Equipment payments are fixed. But you can control what you pay for ingredients, how much food gets wasted, how you schedule staff, and whether labor is efficient during slow periods. These two line items typically account for 55% to 65% of every dollar you bring in.

Industry benchmarks put healthy prime cost between 55% and 65% of revenue. Full-service restaurants with extensive menus and more labor-intensive service tend toward the higher end. Quick-service operations with simpler menus and less table service can run leaner. If your prime cost consistently exceeds 65%, profitability becomes nearly impossible unless your rent is unusually low or you’ve built significant volume.

A high prime cost usually means one of three things. Food costs are too high relative to menu prices. Labor is bloated or inefficiently scheduled. Or waste is eating into your margins. Each requires a different fix. Raising menu prices helps food cost percentage but might hurt volume. Cutting staff saves labor but might hurt service quality. Reducing waste helps both but requires better inventory and prep systems.

Track prime cost weekly, not monthly. Monthly is too late. By the time you see February’s numbers in mid-March, you’ve already lost six weeks of opportunity to adjust. Weekly tracking lets you spot problems while there’s still time to react. An Andover, MA payroll service that understands restaurants can help you get labor data quickly enough to make this tracking practical.

Break it down further when possible. Know your food cost and labor cost separately so you can identify which component is causing problems. A restaurant running 30% food cost and 35% labor has a labor problem. One running 38% food cost and 28% labor has a purchasing or waste problem. The total prime cost might be similar, but the solutions are completely different.

Restaurant accounting requires tracking metrics that other businesses don’t worry about. Prime cost is the foundation. Once you’re tracking it consistently, you can start looking at food cost by category, labor percentage by day of week, and cost per cover. But prime cost comes first because nothing else matters if that number is out of control.