Most restaurants lose €3,000-5,000 annually by ignoring food waste in their cost calculations. Setting a realistic waste percentage helps you calculate your cost prices correctly and prevents you from losing money through overly optimistic estimates. Establishing a fair waste percentage for each product isn't complicated once you know what to measure.
What is a realistic waste percentage?
A waste percentage shows what proportion of your purchased product you can't use. This happens due to peels, pits, bones, or spoilage. It's the difference between your purchase weight and usable weight.
? Example:
You buy 10 kg of potatoes for €12.00
- After peeling you have 8.5 kg of usable potato
- Waste: 1.5 kg of peels
- Waste percentage: (1.5 / 10) × 100 = 15%
So you're actually paying €1.41 per kg of usable potato (€12 / 8.5 kg)
Why waste percentages matter so much
Many restaurant owners calculate based on the purchase price per kilo, but forget to factor in waste. This makes your cost prices seem lower than they really are.
- Underestimating costs: You think salmon costs €18/kg, but after filleting you're paying €32/kg
- Too low selling prices: Your food cost becomes higher than planned
- Loss of profit: Each dish generates less revenue than you thought
⚠️ Note:
Waste percentages vary by supplier, season, and quality. So measure regularly again.
Typical waste percentages by product group
As a starting point you can use these guidelines, but always measure yourself for your specific suppliers:
Meat and fish
- Whole fish → fillet: 40-55% waste
- Whole chicken → fillet: 35-45% waste
- Beef trimming: 15-25% waste
- Pork loin cleaning: 10-20% waste
Vegetables
- Peeling potatoes: 15-20% waste
- Peeling carrots: 10-15% waste
- Peeling onions: 8-12% waste
- Cleaning lettuce: 15-25% waste
? Example calculation:
Whole salmon of 3 kg for €54.00 (€18/kg)
- After filleting: 1.5 kg fillet (50% waste)
- Actual fillet price: €54 / 1.5 kg = €36/kg
- Difference from purchase price: €36 - €18 = €18/kg extra
If you calculate with €18/kg, you lose €18 per kg of fillet
How to measure waste in practice
The only way to get a realistic waste percentage is by measuring. Do this for your most important ingredients:
Preparation
- Choose a normal work moment (not during the rush)
- Make sure you have a clean scale
- Measure at least 3 times for an average
- Write down everything immediately
The measurement process
- Weigh the product upon arrival (remove packaging)
- Process the product normally (as you always do)
- Weigh the end result (usable part)
- Calculate the difference and the percentage
? Practical example:
Measurement of 5 kg onions over 3 days:
- Day 1: 5.0 kg → 4.6 kg (8% waste)
- Day 2: 5.0 kg → 4.5 kg (10% waste)
- Day 3: 5.0 kg → 4.4 kg (12% waste)
Average waste percentage: 10% - use this in your calculations
From waste percentage to actual cost price
Once you know the waste percentage, you can calculate the actual cost price per kilo:
Formula: Actual price = Purchase price / (1 - Waste percentage)
? Calculation example:
Potatoes: €1.20/kg, 18% waste
- Yield: 100% - 18% = 82%
- Actual price: €1.20 / 0.82 = €1.46/kg
- Extra costs: €0.26 per kg
At 100 kg per month: €26 extra costs you'd otherwise miss
Things most kitchen managers discover too late
Waste percentages change due to various factors. Most don't realize how quickly these shifts can impact their bottom line until they've lost serious money:
- Season: Vegetables in season have less waste
- Supplier: Different quality = different waste percentage
- Staff: New employees create more waste
- Storage: Longer storage = more spoilage
⚠️ Note:
Measure again if you switch suppliers or if you notice suddenly much more or less waste.
Recording waste in your system
Good record-keeping helps you spot patterns and calculate costs accurately. Note with each measurement:
- Product and supplier
- Date and time
- Purchase weight and usable weight
- Who processed it (differences possible per person)
- Special notes (poor quality, rush, etc.)
Digital systems can keep this data organized and automatically calculate these percentages into your cost prices, so you always work with realistic figures.
How do you determine a realistic waste percentage? (step by step)
Choose your most important products
Start with the 5-10 ingredients you use most or that are most expensive. This has the biggest impact on your cost prices.
Measure the purchase weight
Weigh the product immediately after delivery, without packaging. Write down the exact weight and supplier.
Process the product normally
Peel, cut, or prepare the product as you normally do. Don't work extra carefully - you want the real waste percentage.
Weigh the usable part
Weigh what you can actually use. Add up all waste: peels, pits, bones, bad parts.
Calculate the waste percentage
Use the formula: (Waste weight / Purchase weight) × 100. Repeat this 3 times and take the average.
Calculate the actual cost price
Divide your purchase price by (1 - waste percentage) to see what you're actually paying per usable kilo.
✨ Pro tip
Measure waste percentages during actual prep sessions over a full week, not just one test run. Proteins consistently show 8-12% higher waste during busy kitchen periods versus controlled measurements.
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Frequently asked questions
How often should I measure waste percentages again?
Should I include waste that occurs from poor storage?
What if my waste percentage is much higher than the standard?
How do I deal with seasonal differences in waste?
Should I track waste per employee?
Can small variations in waste percentage really affect my profits?
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
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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