A worked food cost variance example, the six causes behind most gaps between actual and theoretical food cost, and the week-long tests that tell you which one is costing you money.
Variance is the gap between actual food cost (what you really spent, from invoices and inventory counts) and theoretical food cost (what you should have spent if every recipe was followed exactly). Knowing the gap exists is the easy part. This guide is about the harder part: putting a number on it for a real menu, and finding out where it comes from.
A Worked Variance Example
Here is one month at a mid-sized restaurant. First, actual food cost from the inventory counts and every food invoice paid in the period:
| Component | Amount |
|---|---|
| Beginning Inventory | $15,500 |
| Purchases (all invoices) | $29,000 |
| Ending Inventory | $14,800 |
| Actual COGS | $29,700 |
| Food Revenue | $88,000 |
| Actual Food Cost % | 33.8% |
To calculate theoretical food cost, you need two things: the plate cost of every menu item, and the number of units sold (from your POS).
| Menu Item | Ideal Plate Cost | Units Sold | Total |
|---|---|---|---|
| Chicken Parm | $6.40 | 180 | $1,152 |
| Grilled Salmon | $12.80 | 95 | $1,216 |
| Caesar Salad | $2.90 | 220 | $638 |
| Burger | $5.20 | 310 | $1,612 |
| Pasta Primavera | $3.70 | 140 | $518 |
| Steak Frites | $16.50 | 75 | $1,238 |
| All other items | — | — | $18,626 |
| Total Theoretical COGS | $25,000 |
Theoretical Food Cost % = ($25,000 ÷ $88,000) × 100 = 28.4%
| Metric | Value |
|---|---|
| Actual Food Cost % | 33.8% |
| Theoretical Food Cost % | 28.4% |
| Variance | 5.4 percentage points |
| On $88,000 revenue | $4,752/month lost |
| Annualized | $57,024/year |
A 5.4-point variance means nearly $5,000 per month is being lost to factors the kitchen isn't fully controlling.
The Six Causes Behind Most Variance
Almost every gap between actual and theoretical food cost traces back to one or more of these six causes. Work through them in order: the first two are usually the largest.
1. Over-portioning — usually the largest single contributor
If the recipe calls for 6 oz of protein and the line puts out 7.5 oz, that's a 25% increase in protein cost per plate. Across hundreds of plates per week, this alone can account for half the variance.
2. Waste and spoilage
Prep waste (trimming), overproduction (making too much of something that doesn't sell), spoilage (food expiring in storage), and cooking errors (burned or dropped plates).
3. Theft and unauthorized consumption
Taking food home, eating off the line, giving friends and family free food without tracking it as a comp.
4. Unrecorded comps and employee meals
Comps that aren't entered in the POS still use food but don't generate revenue. If $800/month in comps isn't tracked, your actual food cost includes the cost of that food while your revenue doesn't.
5. Recipe costing errors
If your recipe costs haven't been updated since ingredient prices changed, your theoretical food cost is wrong — and the variance is misleading.
6. Receiving errors
Short deliveries (you were charged for 5 cases but received 4), substitutions at different prices, or items arriving at a different weight than invoiced.
How to Find Which Cause Is Yours
Update every recipe with current vendor prices. If chicken breast was $2.10/lb when you costed the recipe but it's now $2.80/lb, your theoretical cost is artificially low and the variance is artificially high.
For one week, place a waste log near each trash can in the kitchen. Every time something goes in, the cook writes down: item, quantity, reason (spoilage, overproduction, error, trim). Tally it at week's end.
During service, weigh plates coming off the line and compare to recipe spec. Do this randomly, without warning, for 3–5 days. The results usually reveal which cooks are heavy-handed and which items have the most variance.
Proteins are typically 40–60% of food cost. Count steaks, salmon portions, shrimp, and other expensive items at the start and end of each day. Compare to POS sales. If 50 steaks were available and only 43 were sold, where did the other 7 go?
Require every comp to go through the POS. Set a clear staff meal policy (e.g., one meal per shift, max $10 plate cost). Track the total monthly.
Keeping the Actual Cost Side Current
The biggest challenge in running this analysis is keeping your actual food cost data up to date. That means tracking every invoice and counting inventory regularly.
Wox helps with the actual cost side — photograph your invoices with your phone, and the app reads and tracks every item and price automatically. No spreadsheets, no manual entry, and the basic features are free. Combined with regular inventory counts and POS data, you have everything you need for a complete actual vs. theoretical analysis.
| Frequency | Best For |
|---|---|
| Weekly | High-volume restaurants, kitchens with known variance issues |
| Bi-weekly | Most independent restaurants |
| Monthly | Minimum standard |
The more frequently you compare actual to theoretical, the faster you catch and fix problems.
Break Variance Down by Category
Actual food cost tells you what you spent. Theoretical food cost tells you what you should have spent. The gap — the variance — reveals how much money is being lost to waste, theft, over-portioning, and operational inefficiency. For most restaurants, this gap is 3–6 percentage points, representing thousands of dollars per month. Close the gap, and that money flows straight to your bottom line.
Breaking down food cost by menu category reveals where your money actually goes. Instead of looking at one blended number, you can see which categories are on target and which need attention.
| Category | Method | Frequency |
|---|---|---|
| Proteins | Track by item, weigh daily | Daily counts on expensive items |
| Produce | Track aggregate spend vs revenue | Weekly |
| Dairy | Track aggregate spend | Weekly |
| Dry goods | Track aggregate spend | Monthly (stable prices) |
Most restaurants find that 2–3 categories drive 80% of their food cost variance. Identifying those categories lets you focus your improvement efforts where they'll have the biggest impact.
Plan Around Seasonal Prices
Seasonal pricing affects food cost significantly. Restaurants that build seasonal flexibility into their menus can save 10–15% on produce during peak seasons and avoid the 2–3× markups that come with buying out-of-season.
| Season | Cheaper Ingredients | More Expensive |
|---|---|---|
| Spring | Asparagus, peas, strawberries, artichokes | Root vegetables, citrus |
| Summer | Tomatoes, corn, stone fruit, peppers, zucchini | Leafy greens (heat stress) |
| Fall | Squash, apples, root vegetables, mushrooms | Berries, tropical fruit |
| Winter | Citrus, cabbage, hearty greens, potatoes | Tomatoes, fresh herbs, berries |
Building your specials around what's in season reduces food cost and improves quality — a rare win-win.
A Cost Control Routine That Holds
Food cost improvement isn't a one-time project — it's an ongoing process. The best operators build systems that make cost control automatic:
Daily: Check deliveries, enforce FIFO, log waste, count expensive proteins.
Weekly: Count inventory, calculate food cost percentage, review waste log, spot-check portions.
Monthly: Run actual vs. theoretical analysis, update recipe costs with current prices, review vendor pricing trends.
Quarterly: Get competitive vendor quotes on top 20 items, conduct menu engineering analysis, adjust menu prices if needed.
The most time-consuming part of food cost management is processing invoices and tracking ingredient prices. Manual entry takes hours per week and is prone to errors.
Tools like Wox automate this entirely — photograph any invoice with your phone, and the app reads every line item, price, and vendor. Your food cost data stays current without manual spreadsheet work. The core features are completely free, making it accessible for any independent restaurant regardless of budget.
Where to Start This Week
Calculate your current food cost percentage using the COGS formula. This is your baseline.
Identify your top 5 items by spend. These drive the majority of your food cost.
Check vendor pricing on those top 5 items — get at least one competitive quote.
Start a waste log near the kitchen trash. Track for one week.
Weigh 5 random plates during service and compare to recipe spec.
These five actions take less than 2 hours total and will give you a clear picture of where your food cost stands and where the biggest opportunities are.
Controlling food cost in this category requires knowing your numbers, tracking them consistently, and acting on what you find. The restaurants that thrive aren't the ones with the lowest ingredient costs — they're the ones that know exactly what their costs are and manage them systematically. Start with the basics: calculate your food cost weekly, cost your recipes with current prices, and address the biggest variances first. The math is simple; the discipline is what separates profitable operations from the rest.