Prime cost: the one number that tells you if you’ll make it

If you could track only one number in your restaurant, it should be prime cost. Food cost alone can look fine while labor sinks you; labor can look fine while food creeps. Prime cost combines the two — the costs you most control — into a single honest read on whether the doors stay open.

What prime cost is

Prime cost = cost of goods sold (food + beverage) + total labor (wages, salaries, payroll taxes, and benefits). Divide it by sales and you get your prime cost percentage. Everything left over after prime cost has to cover rent, utilities, equipment, marketing — and profit. That’s why it’s the number: it’s the biggest slice, and the one you can actually change week to week.

What a healthy number looks like

For most full-service restaurants, a prime cost around 60% of sales or below is the target; quick-service can often run a little lower. Above ~65% and profit gets very thin very fast. These are guidelines, not gospel — a high-rent location or a premium concept shifts the math — but if your prime cost is drifting toward 70%, something needs attention now, not at year-end.

Calculate it (a worked example)

Say a week did $40,000 in sales. Food + beverage cost was $12,000 (30%) and total labor was $13,000 (32.5%). Prime cost is $25,000, or 62.5% of sales. That’s close to target — a small trim in either lever pulls it under 60%. The power is in seeing both together: if you’d only watched food (a healthy 30%), you’d have missed that labor was doing the damage.

Track it weekly, not monthly

Monthly prime cost tells you what already happened. Weekly prime cost lets you steer. Same day each week, pull your food cost (from a focused inventory count) and your labor (from the schedule and timeclock), add them, divide by the week’s sales. One number, one trend line. When it ticks up, you’ll usually know which lever moved — and you can act while the month is still savable.

Move the number with the two levers

Prime cost only has two dials, which is what makes it manageable. If it’s high, ask: is it food (portioning, waste, vendor prices) or labor (overstaffing, overtime, slow-hour coverage)? Diagnose which half is off, fix the bigger one first, and re-measure next week. You don’t need to optimize everything — you need to know which dial to turn.