Every month, restaurant owners discover thousands slipping through their fingers. Money vanishes through oversized portions, outdated pricing, and invisible waste. Here are 5 rapid checks that reveal exactly where your profit disappears.
The 5 biggest leaks in every kitchen
Most entrepreneurs only realize at month's end that there's nothing left. But warning signs appear daily. You just need to know where to look.
💡 Example:
Restaurant The Golden Spoon turns over €8,000 per week. But owner Mark spots these leaks:
- Chef gives 250g steak instead of 200g: €240/week extra
- Food cost pasta carbonara: 38% instead of 30%: €180/week
- Vegetable waste from poor planning: €120/week
Total leak: €540 per week = €28,080 per year
Check 1: Food cost of your bestsellers
Start with your 5 top-selling dishes. These determine 80% of your profit. Calculate food cost using this formula:
Food cost % = (Ingredient costs / Selling price excl. VAT) × 100
- Above 35%? You're hemorrhaging money on this dish
- Between 28-35%? Solid margin
- Below 28%? Consider upgrading quality
⚠️ Attention:
Always calculate with price EXCLUDING VAT. €32 incl. 9% VAT = €29.36 excl. VAT. Many entrepreneurs forget this and think their food cost is lower.
Check 2: Portion size vs. recipe card
Spend an evening in the kitchen. Weigh what your chef actually serves versus what's written on recipe cards. A mere 20-gram meat difference per portion can cost €3,000+ annually.
💡 Example calculation:
Steak recipe: 200g, chef gives: 220g
- Difference: 20g extra per portion
- Beef: €24/kg = €0.024/gram
- Extra cost: 20g × €0.024 = €0.48 per portion
- 50 portions/week × 52 weeks = €1,248/year
Check 3: Trimming loss and waste
How much of your purchases ends up in trash bins? Track everything you discard for one full week. This reveals your true waste picture.
- Vegetables: normal 10-15% trimming loss
- Fish (whole to fillet): 40-50% loss
- Meat (whole to portions): 15-25% loss
Check 4: Prices vs. purchase prices
Last menu update? Suppliers raise prices regularly, but many entrepreneurs forget to adjust their menus accordingly.
💡 Example impact:
Beef rose from €20 to €24/kg (+20%). You didn't raise your menu price.
- Extra cost per 200g portion: €0.80
- 40 steaks per week: €32/week extra
- Per year: €1,664 less profit
Check 5: Revenue vs. purchase ratio
Quick health check: compare weekly purchases with revenue from that same week. Based on real restaurant P&L data, typically:
- Food cost 30% = purchases should be ±30% of revenue
- Much higher? You're buying too much or losing too much
- Much lower? Check if you're understocking
Digital tools
Manual tracking consumes enormous time. Apps like KitchenNmbrs automatically calculate food cost per dish and alert you when you exceed target percentages. You'll see immediately where action's needed.
How do you do the leak check? (step by step)
Gather data from your top 5 dishes
Note for your 5 best-selling dishes: menu price, ingredient cost per portion, and how many you sell per week. You need these figures for all further calculations.
Calculate the actual food cost per dish
Use the formula: (Ingredient costs / Selling price excl. VAT) × 100. Note: at 9% VAT, divide the menu price by 1.09 to get the price excl. VAT.
Measure all waste for one week
Weigh everything that goes in the trash: trimming waste, spoiled products, leftovers from plates. Add up the value and compare with your total purchases that week.
Compare actual portions with recipe card
Weigh what your chef actually gives during a busy service. Note deviations and calculate the extra cost per portion and per year.
Create an action plan for the biggest leaks
First tackle the leak that costs you the most money. Usually that's the food cost of popular dishes or oversized portions of expensive ingredients.
✨ Pro tip
Track your Saturday night food costs within 48 hours every week. Weekend shifts often have different kitchen staff who portion generously, and catching these 5-10% overages early prevents monthly profit disasters.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
How often should I do this leak check?
Do the complete check monthly. But monitor your top 5 dishes weekly - these determine the biggest chunk of your profit.
What is an acceptable waste percentage?
For restaurants, 5-8% waste is normal. Above 10% gets expensive. Count both trimming waste and spoiled products.
Should I check all dishes or just the popular ones?
Start with your top 5 bestsellers. These make up 70-80% of your revenue. Fix those first, solve the biggest problem.
How do I know if my chef is giving oversized portions?
Weigh 10 portions of the same dish during busy service. On average more than 10% deviation from your recipe? Money's leaking away.
What if my food cost comes in above 35%?
Three options: raise menu price, use cheaper ingredients, or reduce portions. Start with price increase - biggest impact on profit.
Do weekend shifts typically show different food costs than weekdays?
Yes, weekend staff often portion differently than weekday teams. Monitor weekend food costs separately to catch these variations early.
📚 Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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