Most restaurant owners think they know their protein costs, but they're often wrong by 50% or more. The culprit? Trimming loss that gets ignored in cost calculations. Your actual cost per portion is much higher than your purchase price suggests.
What is trimming loss and why does it cost money?
Trimming loss represents the gap between what you purchase and what actually reaches the plate. For meat, you're dealing with fat, bones, and unusable sections. Fish brings its own challenges: heads, bones, skin, and fins all add weight but zero value to your final dish.
💡 Example:
You buy 2 kg whole salmon for €18/kg:
- Purchase price: 2 kg × €18 = €36
- After filleting: 1.1 kg clean fillet
- Trimming loss: 0.9 kg (45%)
Actual fillet price: €36 ÷ 1.1 kg = €32.73/kg
That salmon isn't costing you €18/kg—it's €32.73/kg. You're paying 82% more than your invoice suggests!
The formula for trimming loss
Two calculations will reveal your true protein costs. First, determine your loss percentage, then calculate the real cost per usable kilogram.
Step 1: Trimming loss percentage
Trimming loss % = ((Purchase weight - Usable weight) ÷ Purchase weight) × 100
Step 2: Actual cost per kilo
Actual price/kg = Purchase price/kg ÷ (Yield % ÷ 100)
Where: Yield % = 100% - Trimming loss %
⚠️ Important:
Divide by the yield, don't multiply. You have less product, so it becomes more expensive per kilo.
Common trimming losses per product
Different proteins carry different loss rates. Here's what you can expect from years of working in professional kitchens:
- Beef (whole to portions): 15-25%
- Fish (whole to fillet): 40-55%
- Shrimp (unpeeled): 35-50%
- Chicken (whole to fillet): 30-40%
- Lamb (leg to portions): 20-30%
These percentages serve as starting points. But measure your own losses for accurate costing.
💡 Beef example:
You buy a whole ribeye of 3 kg for €28/kg:
- Purchase price: 3 kg × €28 = €84
- After boning: 2.3 kg steaks
- Trimming loss: 0.7 kg (23%)
- Yield: 77%
Actual steak price: €28 ÷ 0.77 = €36.36/kg
Accounting for trimming loss in your cost per portion
Once you've calculated the true cost per kilogram, portion costing becomes straightforward. Always use your actual price—never the purchase price from your invoice.
💡 Portion cost example:
Salmon fillet of 180 grams per portion:
- Actual fillet price: €32.73/kg
- Portion: 180 grams = 0.18 kg
Cost per portion: €32.73 × 0.18 = €5.89
Using the purchase price of €18/kg would give you €3.24 per portion. That's a €2.65 underestimate per plate—multiply that across hundreds of covers, and you're looking at serious profit erosion.
Minimizing trimming loss
Reducing waste directly improves your bottom line. Focus on these areas:
- Choose the right supplier: Some deliver better processed products
- Train your staff: Proper knife skills reduce unnecessary waste
- Use the scraps: Transform bones and heads into valuable stock
- Measure regularly: Track your actual losses consistently
Tools like a food cost calculator help you automatically factor trimming losses into your calculations, ensuring you never underestimate what your dishes actually cost.
How do you calculate trimming loss in 3 steps?
Measure the trimming loss percentage
Weigh your product before and after processing. Calculate: ((purchase weight - usable weight) ÷ purchase weight) × 100. This gives you the trimming loss percentage.
Calculate the actual cost per kilo
Divide your purchase price by the yield percentage (100% - trimming loss%). If you have 25% loss, divide by 0.75. This gives you the actual price per kilo of usable product.
Calculate what one portion costs
Multiply the actual price per kilo by the weight of your portion in kilos. A portion of 200 grams = 0.2 kg. This is your cost per portion including trimming loss.
✨ Pro tip
Weigh and measure trimming loss on your 3 highest-volume proteins over the next 2 weeks. These items have the biggest impact on your food costs and profit margins.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
Was this article helpful?
Frequently asked questions
Do I always need to account for trimming loss in my cost?
Absolutely. Ignoring trimming loss means you're underpricing your dishes and killing your margins. With whole fish, your actual costs can be 80% higher than what you paid per kilogram.
Can I estimate trimming loss instead of measuring it?
Don't risk it. Trimming loss fluctuates based on supplier quality, seasonal variations, and product size. Measure it several times with each supplier to get accurate baseline data.
What do I do with the trimming loss scraps?
Turn waste into profit wherever possible. Fish bones become rich stock, chicken scraps enhance soups and sauces. You'll recover some value from your 'loss' while reducing other ingredient costs.
How often should I remeasure my trimming loss?
Test new suppliers immediately, and recheck established ones twice yearly. Product quality shifts with seasons, and supplier practices can change over time.
Why does my product become more expensive after trimming loss?
You're spreading the same total cost across fewer usable kilograms. If you pay €100 for 5kg but only get 3kg of usable product, that €100 is now divided by 3kg, not 5kg.
Should I buy pre-trimmed products to avoid this calculation?
Sometimes yes, sometimes no. Pre-trimmed products cost more per kilogram but eliminate waste and labor. Calculate both scenarios—including your labor costs for processing—to see which option delivers better value.
⚠️ 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.
Selling food? Then you need KitchenNmbrs
Whether you run a restaurant, food truck, catering company, or meal kit business — you need to know what each dish costs. KitchenNmbrs gives you that insight. Start your free trial.
Start free trial →