Cost control
Profitability
Prime cost: the only number that really matters (and how to read it)
Restaurant prime cost is the sum of your cost of goods sold and your total labor cost — and on a P&L, it's the only number that consistently tells you whether you're making money. Most operators glance at it. The good ones obsess over it weekly. Most explainers stop at the formula; we're going to walk through a real monthly P&L, find the leak, and fix it.
Key takeaways
Prime cost = cost of goods sold + total labor cost. A healthy restaurant runs 60–65% of revenue.
Over 70% prime cost, you have a problem. Over 75%, you're losing money even if the bank account looks fine.
The right cadence is weekly — daily is too noisy, monthly catches problems too late.
The 30/30/30/10 rule is a useful benchmark, not a formula. Real numbers vary by concept.
You can't fix a prime cost number you only look at quarterly. The cadence is the work.
You can't fix a prime cost number you only look at quarterly. The cadence is the work.
What is prime cost in a restaurant?
Prime cost is the combination of your cost of goods sold (COGS) — the food and beverage you actually used to generate revenue — and your total labor cost, including hourly wages, salaries, payroll taxes, and benefits. It's expressed as both a dollar amount and a percentage of total sales.
The reason it matters more than any other line item: these are your two largest controllable expenses. Rent doesn't change much month to month. Insurance is what it is. But COGS and labor — those move every shift. Together they make up the bulk of what you can actually influence as an operator. If you only have time to track one number, this is the one.
The benchmark for a healthy restaurant prime cost is 60–65% of total sales. Over 70% and you're in trouble. Over 75% and you're losing money even if your bank account temporarily disagrees with that statement.
How do you calculate prime cost?
The formula is simple:
Prime Cost = Total COGS + Total Labor Cost
Prime Cost % = (COGS + Labor) ÷ Total Sales × 100
Here's a worked example from a hypothetical fast-casual concept doing $200,000 in monthly sales:
Line item | Amount | % of sales |
|---|---|---|
Total sales | $200,000 | 100% |
Food cost | $66,000 | 33% |
Beverage cost | $8,000 | 4% |
Total COGS | $74,000 | 37% |
Hourly labor | $48,000 | 24% |
Salaried labor | $14,000 | 7% |
Payroll taxes & benefits | $8,000 | 4% |
Total labor | $70,000 | 35% |
Prime cost | $144,000 | 72% |
72% prime cost. Bad news. The benchmark for fast casual is 58–64% — so this restaurant is bleeding roughly $16,000–$28,000 per month against where it should be. Annualized, that's $200,000 to $300,000 evaporating somewhere between food cost waste and labor inefficiency.
But which side is the leak on? That's what reading prime cost actually means.
What does good prime cost look like by concept?
There's no single "right" prime cost — it varies by concept. A fine-dining restaurant runs different math than a quick-service drive-thru. Here's where the numbers should land for a healthy operation across the spectrum:
Concept | Food cost % | Labor cost % | Prime cost % |
|---|---|---|---|
Quick service (QSR) | 28–32% | 25–30% | 55–62% |
Fast casual | 28–32% | 28–32% | 58–64% |
Counter-service casual | 30–34% | 25–30% | 58–64% |
Full-service casual | 30–34% | 30–35% | 62–68% |
Full-service upscale | 32–38% | 32–38% | 65–72% |
Fine dining | 30–35% | 35–42% | 68–75% |
Coffee / café | 25–30% | 30–38% | 58–65% |
A few things worth flagging from the table. Fine dining sustains a higher prime cost than other concepts because the price points absorb it — your $48 entrée can carry a 35% food cost in a way that a $14 bowl can't. QSR keeps prime cost lowest because it's engineered for throughput and minimal labor per ticket. And cafés are deceptively labor-heavy — the espresso drinks have great margin but they take real time to make.
When you compare your actual numbers to this table, look at the two halves separately. If both are above the benchmark, you have a structural issue. If only one is, the fix is more focused.
How do you actually fix a high prime cost?
Going back to the example — that 72% prime cost, $16–28K leaking every month. Here's the operator's diagnostic, in order:
Pull the actual numbers, not the POS estimates. Your POS shows you what should have been used (theoretical food cost) based on recipes. Real food cost is: (Beginning Inventory + Purchases − Ending Inventory) ÷ Sales. Most operators are off by 2–4 percentage points until they actually count.
Look at the trend, not the snapshot. A single 72% month is information. A 72% quarter with a steady trend is a structural problem. The fix depends on which.
Split prime cost into its two halves and see which one is broken. In our example, food cost at 37% is high (target 28–32%) but labor at 35% is also high (target 28–32%). Both sides are leaking. If only one were high, the fix would be simpler.
Pick the highest-leverage move. Food cost problems usually trace to four sources: portion drift, vendor pricing, waste, or theft. Labor cost problems usually trace to three: over-scheduling, under-cross-trained teams, or unproductive shifts. Pick the most likely cause based on what you've seen on the floor — and start there.
This is where the missing ingredient shows up. Most operators try to fix prime cost by cutting one big thing. The healthier approach is to find the four small leaks that compound. We'll go deep on the food cost side in a separate post, with another worked example showing exactly where the money disappears.
The bottom line
Prime cost isn't a metric you check once a quarter when your accountant sends the P&L. It's the weekly pulse of your business. Build the cadence — every Monday morning, with last week's numbers — and the leaks become visible before they become structural. That's the difference between an operator who knows what's working and an operator who only finds out after the bank balance moves.
Sources and further reading
The benchmarks in this post draw from multiple industry sources. Specific concept-level ranges are Baby Chef's synthesis from those inputs combined with our consulting experience.
Prime cost benchmarks: aggregated from Restaurant365, Sage, BentoBox, Templi, and Barmetrix.
Real food cost formula (Beginning Inventory + Purchases − Ending Inventory ÷ Sales): standard restaurant accounting practice, documented at Square, Toast, and the National Restaurant Association.
The 30/30/30/10 rule: widely-referenced industry framework with no single attributable origin; clearest published explanations at RestaurantOwner.com and Toast On the Line.
The $200,000 monthly P&L example in this post is illustrative — a hypothetical fast-casual concept used to show how the math works. Real restaurants vary.
Baby Chef is a hospitality consulting team made up of operators who've worked the kitchen, the floor, and the back office. We help independent restaurant owners and small multi-unit operators audit, optimize, and future-proof their operations. Looking for help reading your prime cost — or fixing it? Get in touch with us. We work hands-on with restaurant owners on operational audits, cost control systems, and the weekly cadence that makes the rest of it work.
