A small mistake every day seems harmless, but can cost you thousands of euros per year. A portion of meat of 220 grams instead of 200 grams, an extra splash of olive oil, or a wrongly estimated portion size. You don't see it right away, but you will at the end of the year. In this article you'll learn to calculate exactly what daily mistakes really cost you.
Why small mistakes have big consequences
Your kitchen runs on routine. Every day the same tasks, the same dishes, the same portions. But if that routine contains a small mistake, it multiplies itself 365 days a year.
⚠️ Note:
Most entrepreneurs only see the monthly food cost, not the daily leaks. That's why small mistakes seem unimportant.
The formula for annual impact
To calculate what a daily mistake costs on an annual basis, use this formula:
Annual impact = Extra costs per portion × Portions per day × Working days per year
For most restaurants: 6 days per week × 52 weeks = 312 working days per year.
💡 Example: Too much meat per portion
Your chef gives 220 grams of steak instead of 200 grams:
- Extra meat: 20 grams per portion
- Meat price: €24 per kilo = €0.024 per gram
- Extra costs: 20g × €0.024 = €0.48 per portion
- Sales: 50 steaks per day
Annual impact: €0.48 × 50 × 312 = €7,488
Common daily mistakes
You often see these mistakes in kitchens, with their typical impact:
- Too generous portions: 10-20 grams extra per portion
- Too much garnish: Extra vegetables, sauces
- Inaccurate portioning: No scale, estimating by feel
- Wrong cutting method: More cutting waste than necessary
- Too much mise-en-place: Daily surplus that gets thrown away
💡 Example: Too much olive oil
Every salad gets an extra splash of olive oil:
- Extra oil: 5 ml per salad
- Olive oil: €8 per liter = €0.008 per ml
- Extra costs: 5ml × €0.008 = €0.04 per salad
- Sales: 80 salads per day
Annual impact: €0.04 × 80 × 312 = €998
How to measure the real impact
To know exactly what mistakes cost, you need this data:
- Exact purchase prices: Per kilo, liter or piece
- Actual portion sizes: Not what the recipe says, but what actually ends up on the plate
- Number of portions per day: For each dish separately
- Working days per year: Account for closure days
⚠️ Note:
Measure actual portion sizes for a week. What's on the recipe and what actually happens are often two different things.
From insight to action
Once you know what mistakes cost, you can prioritize. A mistake costing €5,000 per year is worth tackling more than one costing €200 per year.
💡 Example: Prioritization
You find three mistakes in your kitchen:
- Too much meat: €7,488 per year
- Too much olive oil: €998 per year
- Too much parsley: €156 per year
Start with the meat. It has 7× more impact than the olive oil.
A system like KitchenNmbrs helps make these calculations automatically. You enter your actual portion sizes, and immediately see what deviations from the recipe cost on an annual basis.
How do you calculate the annual impact of daily mistakes?
Measure the actual portion size
Weigh all portions of your best-selling dishes for a week. Note the difference with your standard recipe. For example: recipe says 200g, reality is 220g = 20g difference.
Calculate the extra costs per portion
Multiply the difference by the purchase price. With 20g extra meat at €24/kg: 20g × €0.024 = €0.48 extra per portion. Add up all ingredients that deviate from the recipe.
Calculate on an annual basis
Multiply by the number of portions per day and working days per year. Formula: Extra costs per portion × Portions per day × 312 working days. This gives you the total annual impact of this one mistake.
✨ Pro tip
Check your 3 most expensive ingredients every month. Weigh 10 portions and calculate the average. If that's 5% higher than your recipe, it probably costs you thousands of euros per year.
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
Do I need to check all dishes or can I select?
Start with your 5 best-selling dishes. They often represent 70-80% of your revenue. Once you've got those right, you've solved the biggest part of your problem.
How often do I need to check portion sizes?
At least 1× per month a spot check. With new staff or after recipe changes, more often. Small deviations quickly grow into large amounts.
What if my chef says generous portions are good for guests?
Calculate what it costs and then decide consciously. €7,000 per year extra can also be invested in better ingredients or marketing. It's about making a conscious choice, not unconscious leakage.
Can I also calculate this for waste?
Yes, use the same formula. Add up what gets thrown away daily, calculate the purchase value, and multiply by 312 working days. Waste is often even more expensive than generous portions.
How do I prevent staff from giving too generous portions?
Provide clear standards and scales in the kitchen. Show them what mistakes cost on an annual basis. Most chefs want to work precisely, but don't know what the impact is.
📚 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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