Peeling and trimming loss transforms your ingredient costs from what you pay to what you actually use. That whole salmon at €18/kg? It'll cost you €32/kg once filleted. Skip this calculation and you're bleeding money on every plate.
What is peeling and trimming loss?
Peeling and trimming loss represents the gap between your purchase weight and usable weight. You're tossing fish heads, bones, and skin. Peeling vegetables. This waste inflates your ingredient costs beyond the sticker price.
💡 Example:
You buy 2 kg whole salmon for €18/kg = €36 total
- After filleting: 1.1 kg usable fillet
- Loss: 0.9 kg (head, bones, skin, trimming loss)
- Loss percentage: 45%
Actual fillet price: €36 ÷ 1.1 kg = €32.73/kg
The formula for net weight calculation
You've got two paths here, depending on your data:
Method 1: If you know the loss percentage
Actual price per kg = Purchase price ÷ (Yield % ÷ 100)
Where: Yield % = 100% - Loss %
Method 2: If you have weighed the weights
Actual price per kg = (Purchase price × Purchase weight) ÷ Usable weight
⚠️ Heads up:
Many operators mistakenly multiply by the loss percentage. You need to DIVIDE by the yield, since you're left with less product!
Typical loss percentages per product
These figures serve as starting points. Your actual loss varies with supplier quality, seasonality, and knife skills:
- Fish (whole to fillet): 40-55%
- Beef (whole to portions): 15-25%
- Shrimp (unpeeled): 35-50%
- Vegetables (peeling): 15-25%
- Potatoes: 15-20%
- Onions: 8-12%
- Carrots: 10-15%
💡 Example vegetable calculation:
You buy 5 kg potatoes for €1.20/kg
- Purchase price: €6.00 total
- After peeling: 4.1 kg usable (18% loss)
- Yield: 82%
Actual price: €1.20 ÷ 0.82 = €1.46/kg peeled potato
Impact on your food cost
Trimming loss directly hammers your food cost percentage. Calculate with purchase price while your actual cost runs 30% higher? Your entire cost structure crumbles. This represents one of the most common blind spots in kitchen management - operators focus on invoice prices while ignoring yield reality.
💡 Impact example:
Salmon fillet in your dish: 180 grams per portion
- Calculated incorrectly with €18/kg: €3.24 per portion
- Calculated correctly with €32.73/kg: €5.89 per portion
- Difference: €2.65 per portion
At 50 portions per week: €6,890 difference per year!
How do you measure loss in your own kitchen?
Each supplier and season delivers different loss rates. So track your own percentages:
- Weigh the product before processing
- Weigh the usable part after processing
- Calculate the loss percentage
- Update your cost prices with the actual price
Run these measurements quarterly, especially with seasonal items. Tools like KitchenNmbrs eliminate the Excel headache while tracking your real costs.
How do you calculate the actual purchase price? (step by step)
Weigh before and after processing
Weigh your product before processing (for example 2 kg whole salmon). Process the product and weigh the usable part (for example 1.1 kg fillet). Note both weights.
Calculate the loss percentage
Loss % = ((Purchase weight - Usable weight) ÷ Purchase weight) × 100. In our example: ((2.0 - 1.1) ÷ 2.0) × 100 = 45% loss.
Calculate the actual price per kilo
Yield = 100% - Loss % = 55%. Actual price = Purchase price ÷ (Yield ÷ 100) = €18 ÷ 0.55 = €32.73 per kg usable product.
✨ Pro tip
Test your yield percentages with 3 different suppliers over a 2-week period. The supplier with the highest invoice price often delivers the lowest actual cost per usable kilogram.
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 measure loss for every product?
Start with your priciest ingredients and top-selling dishes. Measure loss there several times and use that average. For cheaper products, standard percentages work fine initially.
How often should I update loss percentages?
Seasonal products need updates every 3-4 months, others twice yearly. Switch suppliers? Measure immediately since quality and losses vary dramatically.
What if I don't have time to weigh everything?
Use standard percentages as your baseline. Focus first on your 5 most expensive ingredients - that's where financial risk concentrates.
Can I reduce loss by cutting better?
Skilled butchery saves 5-10% on fish and meat. Thinner peeling helps with vegetables. But always calculate with your actual loss, not wishful thinking.
How do I incorporate this into my cost price calculation?
Always use the true price per kg (post-loss) in your recipes. Calculate with €32.73/kg fillet, not €18/kg whole fish. Your food cost percentage will finally reflect reality.
Should I negotiate with suppliers based on yield rates?
Absolutely. A supplier charging 10% more but delivering 15% better yield saves you money. Track yield data across vendors to make informed purchasing decisions.
⚠️ EU Regulation 1169/2011 — Allergen Information — https://eur-lex.europa.eu/eli/reg/2011/1169/oj
The allergen information on this page is based on EU Regulation 1169/2011. Recipes and ingredients may vary by supplier. Always verify current allergen information with your supplier and communicate this correctly to your guests. KitchenNmbrs is not liable for allergic reactions.
In the UK, the FSA enforces allergen regulations under the Food Information Regulations 2014.
📚 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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