Ask a restaurant owner how the business is doing and you usually get a revenue number. Revenue is the least useful figure on the statement. A restaurant can grow sales every month and lose money faster each time.
The number that answers the question is prime cost.
What prime cost is
Prime cost is your cost of goods sold — food and beverage — plus total labour, expressed as a percentage of sales.
Prime cost = (food cost + beverage cost + total labour) ÷ sales
Total labour means everything: hourly wages, salaried management, payroll taxes, workers compensation and benefits. Not just the wage line.
It matters because these are the two large costs you can actually influence week to week. Rent is fixed for years. Your prime cost can move meaningfully between one week and the next, which makes it the lever you actually have.
Why one number instead of two
Because food cost and labour cost trade against each other, and looking at either alone will mislead you.
Buy pre-portioned proteins and your food cost rises while prep labour falls. Butcher in house and food cost falls while labour rises. Either can be the right call. Looking at food cost alone, the pre-portioned decision looks like a mistake. Prime cost tells you whether the trade actually worked.
The accounting that makes it possible
Here is where most restaurants come unstuck, and it is a bookkeeping problem rather than an operations one.
Food and beverage must be separated
Beverage runs a very different cost percentage from food. Blended together, a strong bar can hide a bleeding kitchen for a long time. Separate cost of sales accounts for food and for beverage, minimum.
All labour must be in labour
Payroll taxes, workers comp and benefits belong in the labour figure. Practices that leave them in general overhead understate prime cost by a wide margin and produce a number that looks fine while the business struggles.
Comps and staff meals need their own home
Comped meals and employee meals buried inside cost of sales inflate food cost and hide the fact that you are giving away more than you think. They belong in their own account where they can be seen and managed.
Purchases are not cost of goods sold
The most common error. What you spent on food this month is not what you consumed. Without an inventory adjustment, a big delivery on the 30th makes a good month look terrible and the next month look excellent. Neither is true.
Even a rough monthly inventory count is far better than none.
Reading the number
Prime cost benchmarks vary by concept — full service differs from fast casual, a bar-heavy operation differs from a bakery — so treat any published target as a rough orientation rather than a rule.
What matters far more than hitting someone else’s benchmark is your own trend. A prime cost that drifts upward two months running is telling you something specific: portioning has slipped, waste has grown, a vendor raised prices quietly, or you are scheduling more labour than the volume supports.
You cannot see any of that on a quarterly close. By the time the number arrives the causes are three months cold.
Weekly, if you can
Monthly prime cost is useful. Weekly is transformative, because it lands while you can still act on it.
A weekly figure does not need to be perfect. Sales from the POS, purchases from invoices received, labour from the scheduling system, and a rough inventory count gets you close enough to spot a trend. The monthly close, with proper inventory and accrual adjustments, is what you rely on for the accurate picture.
The weekly number is a management tool. The monthly number is the financial statement. Both have a job.
Talk it through with a Fresno CPA
We build restaurant charts of accounts so prime cost is a number you can read every month rather than reconstruct at year end. See our restaurant accounting page.
Schedule a meeting or call 559-372-9213.
This post is general information, not advice for your specific situation. Tax figures are current for the year stated and many are indexed annually. Talk to a CPA before acting on any of it.
