How to Calculate Food Cost Percentage (Formula + Example)
You know you’re supposed to know your food cost. It’s the number every article, every rep, every consultant points at. But somewhere between the lunch rush and payroll, you’ve never actually sat down and costed a plate to the cent — and the recipe “feels about right,” so it’s stayed on the never-quite list.
It takes ten minutes per dish. Here’s how to calculate food cost percentage, both ways operators use it, worked all the way through — plus the handful of costs that make your real number higher than the recipe says.
The formula, plainly
There are two versions, and you want both.
Per plate — what one dish costs to make versus what you charge for it:
Food cost % = (plate cost ÷ menu price) × 100
For the whole period — what your kitchen actually burned through last week or last month:
Food cost % = (COGS ÷ food sales) × 100
where COGS = beginning inventory + purchases − ending inventory
The per-plate number is your theoretical food cost — what the dish should cost if everything goes to spec. The period number is your actual food cost — what really happened once you count the over-portioning, the waste, and the comps. The distance between those two is where the money hides. More on that below.
Worked example: costing one plate
Take a grilled chicken sandwich with fries. Cost every component at what you actually pay per unit — from a recent invoice, not from memory:
| Component | Cost |
|---|---|
| Chicken breast (5.5 oz) | $1.60 |
| Brioche bun | $0.40 |
| Lettuce & tomato | $0.20 |
| Aioli | $0.15 |
| Pickle | $0.05 |
| Fries (side, 5 oz) | $0.50 |
| Total plate cost | $2.90 |
The sandwich sells for $10.00. So:
$2.90 ÷ $10.00 × 100 = 29% food cost
That’s it. Twenty-nine percent — comfortably inside the healthy range for full-service. And notice the shape of it: the chicken alone is $1.60, more than half the plate. That’s the norm — the protein is almost always the biggest line, and it’s the one most likely to run heavy, because it’s the one nobody weighs. Cost the plate and you can see exactly which ingredient to watch.
The other number: your actual food cost for the month
The plate math tells you what a dish should cost. To see what your kitchen actually ran, use the period formula. Say last month looked like this:
| Line | Amount |
|---|---|
| Beginning inventory | $8,000 |
| + Purchases | $22,000 |
| − Ending inventory | $7,000 |
| = COGS (food used) | $23,000 |
| Food sales | $80,000 |
| Food cost % | 28.75% |
$23,000 ÷ $80,000 × 100 = 28.75%. That’s your real, all-in number — every plate, every mistake, every freebie, blended together.
Here’s the part that matters: if your recipes say you should be running 26% but the month came in at 28.75%, that ~3-point gap isn’t rounding. It’s real money leaking somewhere between the spec sheet and the pass. A gap that shows up and you can’t explain it is its own diagnosis — why your food cost crept up but nothing “changed” walks through where it usually hides.
Working the formula backward to set a price
The same formula sets your price. If a plate costs $2.90 and you want to hit a 30% food cost, rearrange it:
menu price = plate cost ÷ target % → $2.90 ÷ 0.30 = $9.67
Round to a clean $10 and you’re running 29%. That’s the honest version of “pricing off cost” — start from what the plate actually costs, set your target, and let the math set the floor. (Then sanity-check it against the neighborhood, because the market gets a vote too.)
Where owners fool themselves
The reason your actual number beats your theoretical one is almost never one big thing. It’s a stack of small, invisible costs the recipe card leaves out:
- The oil, the butter, the flour dredge — the cooking mediums nobody costs into the dish.
- The garnish and the “free” bread that goes out with every table.
- Comps, voids, and staff meals — food that leaves the kitchen but never hits a check.
- Yield and waste — the trim, the spoilage, the pan you dropped. You bought a whole case; you didn’t sell a whole case.
- The portion that drifted. The single biggest one. The protein you eyeball creeps from 5.5 oz to 6.5 oz on a busy Friday, and every sandwich quietly costs more than your table says it does.
None of these show up when you cost a plate on paper. All of them show up in the period number. That’s why you calculate both — the plate tells you the target, the period tells you the truth, and the gap tells you where to look.
The honest catch
Costing a plate by hand works. It’s also true for exactly one day. Do it for your top five dishes this afternoon and you’ll learn something real — but next week a supplier nudges a price, the portion drifts, and the numbers you worked out are already stale. Nobody re-costs forty dishes every week against fresh invoices while also running the floor. That’s not a discipline problem. It’s a time problem.
That’s the whole reason Mise exists. You snap a photo of each supplier receipt, and we keep the real cost of every dish updated automatically, against the prices you’re actually paying — so the food cost percentage you calculated once stays current on its own. That’s the short version of how it works.
But you don’t need us to start. Grab a recent invoice, cost your three highest-volume plates the way we did above, and find out what they really run today. If you’d rather it stayed current without the weekly spreadsheet — see what your menu actually costs →
Built by people who’ve worked the line, signed the leases, and stared at the books. We help independent restaurants know what every dish actually costs — and what to do about it.
