Every month, restaurants lose hundreds of euros because they miscalculate cooking loss. That 300-gram steak shrinks to 240 grams after grilling, yet most operators still base their pricing on the original weight. Here's how to fix this costly error.
What is cooking loss?
Cooking loss represents the weight reduction that happens during food preparation. Moisture evaporates and fat renders out. Meat, fish, and vegetables all shed weight during cooking.
💡 Cooking loss examples:
- Beef: 20-30% weight loss
- Pork: 15-25% weight loss
- Chicken: 15-20% weight loss
- Fish: 10-15% weight loss
- Vegetables: 5-15% weight loss
Why cooking loss affects your cost price
You purchase meat by the kilo but serve less weight after cooking. Your actual cost per portion becomes higher than your purchase price indicates.
💡 Calculation example:
You buy steak for €24.00 per kilo and serve portions of 200 grams after grilling.
- Purchase weight per portion: 250 grams (25% cooking loss)
- Cost price per portion: €24.00 × 0.25 kg = €6.00
- NOT: €24.00 × 0.20 kg = €4.80
Difference: €1.20 per portion!
The correct formula for cooking loss
Calculate your actual cost price using purchase weight, not served weight. This is a mistake that costs the average restaurant EUR 200-400 per month.
Formula:
Purchase weight = Served weight ÷ (1 - Cooking loss %)
💡 Step by step example:
You serve a salmon fillet of 180 grams. Salmon has 12% cooking loss.
- Served weight: 180 grams
- Cooking loss: 12%
- Purchase weight: 180 ÷ (1 - 0.12) = 180 ÷ 0.88 = 205 grams
- At €18.00/kg: cost price = €18.00 × 0.205 = €3.69
⚠️ Note:
Never calculate your cost price based on served weight. You need to purchase more than you serve. This common mistake undermines your profit.
Cooking loss per cooking method
Different cooking methods produce varying cooking loss with the same product:
- Grilling/frying: Highest loss due to direct heat
- Roasting in the oven: Average loss
- Poaching/steaming: Lowest loss due to moist cooking
- Sous-vide: Minimal loss due to vacuum sealing
Measuring cooking loss in your kitchen
Every product and kitchen differs. So measure your own cooking loss for main ingredients:
- Weigh the product before preparation
- Prepare as usual
- Weigh again after preparation
- Calculate the loss percentage
💡 Measure this for your bestsellers:
- Your 5 best-selling meat dishes
- Your 3 main fish dishes
- Vegetables you use frequently
Do this multiple times and take the average. This gives you reliable figures for your cost price calculation with tools like KitchenNmbrs.
Impact on your food cost
Ignoring cooking loss can distort your food cost significantly. With meat and fish, this creates a 2-5 percentage point difference in your total food cost.
💡 Impact example:
Restaurant with €500,000 annual turnover, 40% meat/fish on the menu:
- Without cooking loss: 28% food cost
- With cooking loss: 31% food cost
- Difference: 3 percentage points = €15,000 per year
How do you account for cooking loss in your cost price? (step by step)
Measure your actual cooking loss
Weigh your main products before and after preparation. Do this at least 3 times per product and take the average. This gives you reliable percentages for your own kitchen.
Calculate the required purchase weight
Use the formula: Purchase weight = Served weight ÷ (1 - Cooking loss %). For a 200 gram steak with 25% loss, you therefore need 267 grams.
Adjust your cost price calculation
Calculate your cost price using the purchase weight, not the served weight. At €24/kg steak, the cost price becomes €24 × 0.267 = €6.41 instead of €24 × 0.200 = €4.80.
✨ Pro tip
Test cooking loss during peak service hours over 3 consecutive weekends. Rush conditions affect how long proteins sit on the grill, changing your actual loss percentages.
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 account for cooking loss for all ingredients?
Not for everything, but definitely for your main ingredients like meat, fish and vegetables that lose significant weight. For spices and sauces, the impact is usually negligible.
How often should I update my cooking loss percentages?
Check this at least twice per year or when you change suppliers. Different quality meats can have different cooking loss percentages.
Can I use standard percentages from tables?
Start with those, but then measure your own cooking loss. Every product, supplier and cooking method can turn out differently in your kitchen.
What if my chef uses different cooking methods?
Measure the cooking loss per cooking method and use the correct percentage per dish. Grilled steak has more loss than pan-fried steak.
How do I incorporate this into my recipes?
Note both the purchase weight and the served weight in each recipe. This way you know exactly how much to order and what the actual cost price is.
Does marinating affect cooking loss calculations?
Yes, marinated proteins often retain more moisture during cooking. Test your marinated items separately from plain proteins to get accurate loss percentages.
📚 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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