Prime Cost: The Number That Predicts Whether a Restaurant Survives

By Taylor Brewster · June 2026 · 3 min read

If you only track one number in your restaurant, make it prime cost: cost of goods sold plus total labor (wages, taxes, benefits), divided by sales. Healthy operations keep it at or below 60–65%. Above 67% for more than a few weeks and the business is funding itself out of someone's savings account.

Why prime cost beats every other metric

Food cost percentage alone lies to you — a low food cost with bloated labor still bleeds. Labor percentage alone lies the same way in reverse. Prime cost catches the trade-offs between them: scratch kitchens run higher food-labor, heat-and-serve concepts run the opposite, but the sum lands in the same survivable band for everyone. It's the one ratio you can benchmark against any restaurant, any concept.

Calculate it weekly, not monthly

A monthly P&L tells you what went wrong four weeks too late to fix it. The weekly version is simple: purchases (from invoices) ± inventory change + the week's full labor cost, divided by the week's sales. Two hours of bookkeeping that pays for itself the first time it catches a creeping problem — an unnoticed price increase from a distributor, overtime quietly stacking up, a portioning drift on your best seller.

When prime cost is fine and money's still tight

This is the pattern I see constantly: a disciplined operator with a 62% prime cost who still can't figure out where the profit went. The answer is almost always below the prime-cost line — the costs nobody assigns to anyone: 30%+ all-in delivery commissions, a 3.2% effective processing rate, a utility contract that rolled onto holdover pricing two summers ago. Those lines don't have a chef or a manager defending them. They just grow.

That's the entire reason the cost audit exists: prime cost has an owner watching it; the invisible costs need one too.