Theoretical vs actual food cost: find the gap between what you should spend and what you do
Theoretical food cost is what recipes say you should have spent; actual is what invoices say you spent. The gap shows where money leaks.
Recipe costing says last month's menu mix should have consumed €18,400 of ingredients at current prices, and invoices total €19,700 against €46,000 in food sales. That is 40.0% theoretical vs 42.8% actual — a 2.8-point gap worth about €1,300 that month. Nothing says why yet: fillets at 82% instead of 90%, burgers at 210 g instead of 180 g, unrecorded trim, or product walking out the back door. The comparison does not name the culprit, but it proves the leak is real and sizes it in euros.
What the two numbers actually measure
- Theoretical food cost: sum over every item sold of its recipe's ingredient cost — 'what should these sales have consumed?' Wrong yields or stale prices make the benchmark lie.
- Actual food cost: beginning inventory + purchases − ending inventory, divided by food sales — 'what did these sales consume, including everything lost?'
- Yield loss and portion variance: 20 kg of raw chicken at 70% usable yield delivers 14 kg, not an optimistic recipe's 18 kg; ten extra grams on 120 covers a day is 1.2 kg given away silently.
- Unrecorded waste and removal: spoilage, dropped pans and over-prep binned without a log land in actual but never theoretical — as does product leaving without a sale.
Tracing a 2.8-point cost gap
A 60-seat restaurant compares both by category for March. Food sales were €46,000. Purchases plus inventory movement totaled €19,700.
| Meat & poultry | Theoretical €7,900 / actual €8,610 | +€710 gap, 9% — check portions first |
|---|---|---|
| Fish | Theoretical €3,100 / actual €3,530 | +€430 gap, 14% — check fillet yield |
| Dairy & produce | Theoretical €3,800 / actual €3,950 | +€150 gap, 4% — likely spoilage |
| Beverage (food-costed) | Theoretical €3,600 / actual €3,610 | +€10 gap, 0.3% — no action |
Category-level comparison points at fish and meat instantly. An overall 2.8% gap looks tolerable; the 14% fish gap inside it is not.
Running the comparison
- 1Reprice the recipes. Set ingredient costs to current invoice prices first, or supplier inflation masquerades as kitchen variance.
- 2Compute both numbers per category. Theoretical: sold quantity × recipe cost. Actual: category purchase spend adjusted for inventory change. Minimum monthly, weekly in a known problem.
- 3Investigate the worst gap, not the loudest theory. Rank categories by euro gap. Weigh three fillets and ten patties off the pass, check the waste log. An hour of measurement beats a month of suspicion.
- 4Fix, then re-measure next period. Retrain the line, correct the yield or start a waste log. If the gap closes within two periods, you found it.
FAQ
- How often should I compare theoretical and actual food cost?
- Monthly, aligned to your stocktake. Weekly helps while chasing a gap but costs more.
- Is some variance always expected?
- Yes. Under ~2% of food sales is noise: rounding, natural yield variation, small unlogged waste. Above 4% two periods running, investigate.
- Does a gap mean someone is stealing?
- Rarely at first. Yield assumptions and portion drift explain most gaps, then unlogged waste. Theft is the residual — a conclusion, not an assumption.
- Do I need software to run this comparison?
- Not necessarily. Accurate recipe costs, current prices, two clean stocktakes — a spreadsheet handles it. Software pays off with fast-changing menus or weekly runs.
Keep reading
- Recipe costing: know the real cost of every plate
Accurate recipe costing converts pack prices into edible yield, batch cost and a defensible plate cost, including sauces and garnish.
- Inventory management for restaurants: the system that keeps your margins honest
What restaurant inventory management actually covers, where losses hide, and how to build a system that catches them.
- Restaurant stocktaking: a fast count that explains your food cost
A repeatable stocktake freezes movement, counts in one direction, reconciles units and investigates variances before month end.
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