Food cost when there's waste

Quick answer

Kitchen waste costs restaurants far more than most owners realize. A kilo of onions might cost €2, but after peeling you're left with just 900 grams - meaning your actual cost jumps to €2. 22 per kilo of usable product.

Kitchen waste costs restaurants far more than most owners realize. A kilo of onions might cost €2, but after peeling you're left with just 900 grams - meaning your actual cost jumps to €2.22 per kilo of usable product. Here's how to calculate your real food costs including waste and trim loss.

Why waste increases your food cost

Most restaurant owners calculate costs based on purchase price per kilo. But waste means you get less usable product for the same money. This drives up your actual food cost per portion.

? Example:

You buy 5 kg salmon for €90 (€18/kg). After filleting you have 2.8 kg fillet left:

Purchase price: €18/kg
Waste: 44% (head, bones, skin)
True fillet price: €18 ÷ 0.56 = €32.14/kg

You're paying almost 80% more than you think!

The difference between purchase price and true food cost

The formula is straightforward but essential:

True food cost = Purchase price ÷ (Yield ÷ 100)

Where yield = 100% minus waste percentage

⚠️ Attention:

Don't multiply by the waste percentage. You have less product, so it becomes more expensive. Always divide by the yield.

Typical waste per ingredient

These percentages provide a starting point. Measure yourself for precise figures:

Fish (whole to fillet): 40-55% waste
Beef (trimming): 15-25% waste
Vegetables (peeling): 15-25% waste
Shrimp (peeling): 35-50% waste
Fruit (peeling, pits): 20-40% waste
Onions (peeling): 8-12% waste

Impact on your food cost

After managing kitchen operations for nearly a decade, I've seen waste dramatically increase food costs without owners realizing:

? Example steak:

Menu price: €32 incl. VAT (€29.36 excl. VAT)

Beef: €24/kg, 200g portion = €4.80
Trimming 20%: true price €30/kg = €6.00
Other ingredients: €3.50

Food cost: €9.50 ÷ €29.36 = 32.4% (instead of 28.2% without waste)

Tracking waste in practice

Measure your waste for a week on the most expensive ingredients:

Weigh before processing
Weigh after processing
Calculate the percentage
Update your food costs

Using tools like KitchenNmbrs, you can set waste percentages per ingredient. The system then automatically calculates the true food cost for your recipes.

How do you calculate food cost with waste? (step by step)

Measure your waste percentage

Weigh your ingredient before and after processing for a week. Calculate the average waste percentage: (purchase weight - usable weight) ÷ purchase weight × 100.

Calculate the yield

Yield = 100% minus waste percentage. At 25% waste your yield is 75%. This is the percentage of usable product you keep.

Calculate the true food cost

Divide your purchase price by the yield (as decimal). At €20/kg and 25% waste: €20 ÷ 0.75 = €26.67/kg true food cost.

Update your recipes

Use the true food cost in your recipe calculations. Check if your selling prices still work with the higher ingredient costs.

✨ Pro tip

Track waste on your 3 most expensive proteins for exactly 2 weeks. This reveals where the biggest cost impacts hide in your kitchen operations.

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

Should I include waste in my food cost calculations?

Absolutely. Waste increases your true ingredient costs significantly. If you ignore this, your food cost will appear lower than it actually is, leading to pricing mistakes.

How often should I measure my waste percentages?

Measure with new suppliers and seasonal changes. For vegetables this can vary per season, while meat and fish percentages are usually more stable.

Can I sell or reuse kitchen waste?

Some waste can be repurposed: bones for stock, vegetable scraps for compost. But don't count on this revenue - calculate your food cost including waste first.

What if different cooks produce different waste amounts?

Train your kitchen team on standard cutting techniques and portion sizes. Use scales and show them what proper portions look like. Consistency reduces waste and controls costs.

How do I reduce waste without compromising quality?

Buy products that better match your recipes. Sometimes pre-cut ingredients cost more per kilo but less per usable portion due to reduced waste.

Should I track waste daily or weekly?

Start with weekly tracking for your top 10 ingredients by cost. Once you establish patterns, monthly checks are usually sufficient unless you change suppliers.

Does cooking method affect waste calculations?

Yes, different cooking methods create different yields. Roasting reduces weight through moisture loss, while braising might retain more. Factor cooking loss into your calculations too.

ℹ️ This article was prepared based on official sources and professional expertise. While we strive for current and accurate information, the content may differ from the most recent regulations. Always consult the official authorities for binding standards.

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.

8 years kitchen manager at 1NUL8 Group Rotterdam

Expertise: food cost management HACCP kitchen management restaurant operations food safety compliance

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