How to Calculate Prime Cost (Weekly, Not Monthly)

Prime cost is the one number every operator should be watching weekly. Most aren’t. They pull it monthly from the bookkeeper, see “62%” on the report, shrug, and move on. By the time that monthly number lands, the week that broke prime cost is four weeks gone and the second bad week is already two weeks in.

This is the version I wish somebody had walked me through the first time I sat down with a P&L and pretended I understood it.

The formula #

Prime cost is the sum of two things: cost of goods sold (food + beverage) and total labor (wages + payroll burden).

Prime cost % = (COGS + Total Labor) ÷ Total Sales × 100

That’s the headline math. The trick is what goes inside each bucket.

COGS for prime cost includes both food and beverage. Food cost percentage on its own is useful, but it only tells half the story. A restaurant with great food cost (28%) and bad pour cost (28% on beer) still runs hot on prime cost. The bev side is leaking and nobody’s looking at it.

Total labor for prime cost is the fully loaded number. Not just the gross wages on the payroll report. The fully loaded number adds:

• FICA (7.65%)
• Federal unemployment tax (FUTA, ~0.6% on first $7K)
• State unemployment tax (SUTA, varies 1-6%)
• Workers comp insurance (restaurant industry runs 3-7% of payroll depending on state)
• Health insurance contribution (if you offer it)
• Paid time off accrual
• Manager salaries amortized to the week

The fully loaded labor cost runs 25-35% higher than gross wages alone (Restaurant365, Toast). If your weekly gross wage bill is $12,000, your fully loaded labor for prime cost purposes is closer to $15,500-$16,200. Run prime cost on gross wages alone and you’re understating by 4-6 points, then staring at the P&L wondering why your net margin doesn’t match the number you’ve been telling yourself.

Why weekly, not monthly #

The textbook says monthly. Good operators run it weekly. The textbook is wrong, and I’ll die on that hill.

A monthly prime cost number tells you what already happened to four weeks of business. By then it’s a postmortem. Weekly prime cost tells you what is happening right now, while you can still adjust before the second bad week lands. Say you take a weekly hit of 65% prime cost on a 60% target. That’s about 1% of weekly revenue. Catch it in week one and fix in week two and you eat a 1% loss. Wait for the monthly to close and you eat 4% across the period, for the same mistake you could’ve caught on a Monday.

The weekly cadence requires:

1. A real-time inventory count (Sunday night for a Mon-Sun week, or Wednesday for a Wed-Tue week).
2. Sales pulled from POS for the same period.
3. Labor pulled from your time clock with payroll burden applied.

Most independent operators already have all three sitting right there. They just don’t pull them on a schedule. The fix is a forty-minute Monday morning routine. You don’t need to buy software for this.

A worked example #

Take a casual full-service restaurant doing $82,000 in weekly sales.

Food cost for the week:

• Beginning inventory: $14,200
• Purchases: $22,800
• Ending inventory: $13,400
• COGS food: $14,200 + $22,800 − $13,400 = $23,600

Beverage cost for the week:

• Beginning bev inventory: $8,400
• Bev purchases: $5,200
• Ending bev inventory: $7,800
• COGS bev: $8,400 + $5,200 − $7,800 = $5,800

Total COGS: $23,600 + $5,800 = $29,400 (35.9% of sales)

Labor for the week:

• Gross hourly wages: $9,800
• Salaried manager (weekly portion): $1,750
• Payroll burden (FICA, SUTA, workers comp, ~28% blended): $3,234
• Health insurance allocation: $620
• Total labor: $15,404 (18.8% of sales)

Prime cost: $29,400 + $15,404 = $44,804 = 54.6%

That’s healthy for a casual full-service. Industry target band is 55-65% (Restaurant365, Toast). At 54.6%, this operation has room to spend on better ingredients, hold prices steady for a season, or pay people more without putting the model at risk. That’s the spot you want to be in.

Where the 60% benchmark comes from (and when to ignore it) #

The “prime cost should be 60% or less” rule of thumb comes from Restaurant365’s industry survey work and Bo Bennett’s prime cost benchmark series at Baker Tilly. It’s a fine starting reference. As a universal target, it’s wrong, and treating it like gospel is how a pizza shop talks itself into thinking it’s doing fine at 60%.

Better targets by concept:

• QSR / fast food: 55-60% (low food cost, higher labor share due to labor-intensive low-ticket service)
• Fast casual: 55-60%
• Casual full-service: 55-62%
• Fine dining: 60-65% (higher food cost from premium ingredients, higher labor from skilled BOH and higher service ratio)
• Pizza: 50-58% (low food cost, sometimes 22-26%, wins back room on labor)
• Coffee shop / bakery: 55-62%
• Sports bar / pub: 55-62%

The right target for your concept is whatever lets you hit your net profit goal after rent, utilities, marketing, and royalty/franchise fees. For most independents the target gets set by whatever’s left after the fixed costs. If your rent + utilities + insurance + marketing run $24,000/month on $325,000 monthly revenue (7.4%), you need to keep prime cost below about 67% to leave 5-6% net margin. Fixed costs of $14,000/month instead? You’ve got more room. Same business, different lease, different target.

Three numbers to fix first when prime cost runs over 65% #

Prime cost over 65% usually comes from one of three places, and on a bad week it’s all three at once. Here’s where to look.

1. Food cost is too high. Run an inventory variance check. If theoretical food cost says 30% and actual says 35%, that 5-point gap is waste, theft, portion drift, recipe non-compliance, or pricing that never caught up to ingredient cost. Each one has its own fix, and they don’t fix the same way, so figure out which one you’ve got before you start swinging.

2. Labor cost is too high. SPLH and labor cost % tell you different things, and you need both. A 38% labor cost on a $7K Saturday means $2,660 in labor against 14 server hours plus 6 BOH hours plus a manager. If your SPLH target is $125, you should have capped out around 56 labor hours. Ran 80? You over-scheduled. The fix is forecasting and staggered shift starts. It is not firing people, which is where panicked owners go first and it almost never solves it.

3. Beverage program is leaking. Pour cost above the bar-program target (18-24% blended) usually traces back to free pours, comps without manager approval, heavy hands on well drinks, or wine BTG yield problems. The bar leak is the one people miss most. I ran bars for five years and I’ll tell you, a generous bartender who thinks they’re building regulars can quietly cost you more than a slow Tuesday.

Investigate in this order. Pull the food cost variance first, since it’s the cheapest to check and the fastest to fix. Then SPLH by daypart. Then bar variance. Most prime cost over-runs land at 60-70% food cost and 30-40% labor, with the bar costing you a point or two on top.

What this looks like in the calculator #

The prime cost calculator on this site takes food cost, beverage cost, and fully loaded labor (burden multiplier included) and gives you prime cost percentage against concept-specific benchmarks. Plug in your weekly numbers and see where you land against the 55-65% band. The answer points you at whether to dig into food cost, labor cost, or pour cost first.

I built it for the Monday morning forty-minute routine, not a quarterly review. Run it once a week off the same source data and prime cost stops ambushing you on the P&L.

What to do today #

Pull last week’s sales, last week’s inventory count (or estimate ending inventory ±5%, close enough to start), last week’s payroll. Apply a 28% burden multiplier to the gross wages. Run the number. If you’ve never done this weekly, your first one is probably going to sting a little. Good. That sting is the whole point.

Sources: Restaurant365, Toast, Baker Tilly Restaurant Industry Benchmark Report, NRA 2024 Industry Factbook.