The One Number Every Restaurant Owner Should Know By Heart: Prime Cost

If I could get every restaurant owner to track just one number, it would be prime cost.

Not revenue. Not covers per night. Not even net profit — though that's obviously the goal. Prime cost, because it's the number that quietly decides whether all of those other numbers ever add up to something sustainable.

Here's what it is, why the ranges matter more than most owners realize, and how to start watching it before it becomes a problem instead of after.

What Prime Cost Actually Is

Prime Cost = (Cost of Goods Sold + Total Labor Cost) ÷ Revenue

In plain English: it's the combined cost of your food and beverage, plus everything you spend on labor — wages, salaries, payroll taxes, benefits — expressed as a percentage of what actually came in the door.

These two categories, food/beverage and labor, are called "prime" for a reason. They're typically 60–70% of a restaurant's total costs, and unlike rent or insurance, they're the costs you have the most day-to-day control over. You can't renegotiate your lease this week. You can adjust a schedule, tighten a portion size, or catch a supplier price increase before it eats your margin for the next three months.

That's what makes prime cost different from most of the numbers on a restaurant P&L: it's not just a report card, it's a lever you can actually pull.

The Ranges — and Why Each One Matters

✅ 55–60%: Healthy and Sustainable

At this range, you have enough margin left over to cover your fixed costs — rent, utilities, insurance, equipment, debt service — and still walk away with a real profit. This is the zone where a restaurant can absorb a slow month, a broken walk-in, or a bad weather weekend without it becoming a crisis.

Why 55–60% specifically, and not lower? Because getting prime cost artificially low usually means cutting corners that show up somewhere else — running too lean on staff (service suffers, turnover spikes), or cutting portion sizes and quality (guests notice, reviews suffer). The healthy range isn't about starving the number down as far as possible. It's about running efficiently while still delivering the product and experience you're known for.

⚠️ 60–65%: Tight, Worth Watching Closely

This is the range where nothing is on fire yet, but there's very little room for error. A restaurant in this zone is often still profitable — but a single bad month, an unexpected repair, or a slow holiday season can wipe out the cushion fast.

The reason this range deserves real attention (not panic, but attention) is that it's rarely a single cause. It's usually two or three small things stacking on top of each other: a supplier price increase that never got repriced into the menu, a slightly bloated schedule left over from a busier season, some waste in prep that nobody's measuring. None of those individually would sink a restaurant. Together, over a few months, they quietly move you from comfortable to tight.

This is the range where a monthly check-in — not a scramble, just a look — pays for itself many times over.

🚩 65%+: Red Flag

At 65% and above, there usually isn't enough left after food and labor to comfortably cover rent, utilities, and everything else — let alone leave a profit. This is the point where something specific needs to change: pricing, portioning, scheduling, supplier terms, or menu mix. Not "eventually." Now.

Here's the part that catches owners off guard: restaurants almost never fail because of one bad month at 65%+. They fail because prime cost creeps past 65% and stays there for two, three, six months — while everyone is heads-down running service, and nobody's stopped to actually calculate the number. By the time it shows up as a cash problem, it's already been a cost problem for half a year.

Why You Should Track Prime Cost Instead of Food Cost and Labor Cost Separately

This is the part that surprises a lot of owners: watching food cost and labor cost as two separate numbers can actually be less useful than watching them combined.

Here's why. Food cost and labor cost trade off against each other constantly, and not always in a bad way. A restaurant that runs a slightly higher food cost — better ingredients, more generous portions, a menu built around a higher-cost signature dish — might run a lower labor cost because the menu is simpler to execute, or because the food itself is driving repeat business and reviews that a cheaper, more labor-heavy menu wouldn't.

The reverse happens too. A restaurant with tight food cost might be running heavier labor because the menu requires more hands-on prep, more skilled cooks, or more front-of-house attention to execute well.

Neither of those restaurants is doing anything wrong. If you only watched food cost in isolation, you might panic at a "high" number that's actually being offset by efficient labor. If you only watched labor in isolation, you might cut staff in a way that hurts service without actually fixing the underlying profitability problem.

Prime cost sidesteps that trap. It asks the only question that actually matters for sustainability: combined, are these two biggest expenses leaving you enough room to run a healthy business?

What To Do With This Number

You don't need fancy software to start tracking prime cost — though good bookkeeping and reporting make it a lot easier to trust the number you're looking at. At minimum:

• Calculate it monthly, not just at year-end or tax time

• Compare it month over month, not just against an industry benchmark — your own trend line will tell you more than a generic average

• If you're in the 60–65% range, investigate before it becomes 65%+ — check supplier pricing, portion consistency, and whether your schedule matches your actual sales volume

• If you're in the 65%+ range, don't wait for next quarter's numbers to make a change — pull the P&L now and find the specific driver

The Bottom Line

Revenue tells you if you're busy. Prime cost tells you if being busy is actually making you money.

If you own or manage a restaurant, ask yourself right now: do you know your prime cost number off the top of your head? If not, that's the first place to start — not because it's the only number that matters, but because it's the one most likely to tell you something's wrong while you still have time to fix it.

Need help getting clean, reliable numbers you can actually trust every month? Above Advisory works with restaurant owners on bookkeeping, reporting, and the kind of financial clarity that catches problems in month two instead of month eight. Book a free consult to see where your numbers stand.