Food waste costs restaurants an average of 5-15% of their purchases. Many business owners have no idea how much they're actually throwing away, which means they're losing money without even knowing it. In this article, you'll learn step-by-step how to calculate your waste percentage and where your profit is leaking away.
What is waste percentage?
Waste percentage is the portion of your purchases that goes into the trash instead of onto a plate. This includes everything you throw away: spoiled products, failed dishes, excess mise-en-place, and what guests leave behind.
💡 Example:
Restaurant De Keuken purchases €2,500 in ingredients this week:
- Meat: €800
- Fish: €400
- Vegetables: €600
- Dairy: €300
- Other: €400
Waste: €375
Waste percentage: (€375 / €2,500) × 100 = 15%
The formula for waste percentage
The calculation is simple, but you need to track everything:
Waste percentage = (Total waste / Total purchases) × 100
But be careful: you need to count all waste, not just what you consciously throw away.
Types of waste you need to count
- Spoilage: Products that pass their expiration date
- Preparation: Failed dishes, burnt pans
- Overproduction: Too much mise-en-place, leftover soup
- Plate waste: What guests leave behind (difficult to measure)
- Trim loss: Peels, bones, unusable parts
⚠️ Important:
Trim loss isn't waste if you plan for it in advance. Only unexpected loss counts as waste.
How to track your waste
Most restaurants don't keep a waste log. That's a missed opportunity, because you can learn a lot from it.
Track daily:
- Write down what you throw away and why
- Estimate the weight or value
- Note the reason: spoilage, failure, overproduction
💡 Example waste log:
Monday, January 15:
- 2 kg potatoes (spoiled): €3.00
- 1 liter soup (leftover): €8.00
- 500g ground meat (burnt): €7.50
- Lettuce (yellowed): €4.00
Daily waste: €22.50
Benchmarks: what's normal?
Waste percentages vary by kitchen type:
- Fine dining: 8-12% (more fresh products)
- Bistro/brasserie: 5-10%
- Casual dining: 6-12%
- Fast food: 3-8% (more shelf-stable products)
Above 15% is high. Below 5% is excellent (or you're not measuring everything).
What you can do with the numbers
Once you know where you're wasting, you can take action:
For high spoilage: Buy smaller quantities, apply FIFO (first in, first out)
For overproduction: Better estimate how much you need, adjust mise-en-place
For preparation mistakes: Team training, standardize recipes
💡 Impact on annual basis:
A restaurant with €150,000 annual purchases:
- At 15% waste: €22,500 loss
- At 8% waste: €12,000 loss
Difference: €10,500 per year through better control
Digital tracking vs. paper
Many kitchens work with a notepad on the fridge. That works, but you lose overview. With an app like KitchenNmbrs you can track waste by category and see trends over multiple weeks.
The advantage of digital: you can easily look back at which month was worst and what caused it.
How to calculate waste percentage? (step by step)
Track everything you throw away for one week
Write down daily what goes into the trash: spoiled products, failed dishes, excess mise-en-place. Estimate the weight or calculate the purchase value. Also note the reason: spoilage, overproduction, or preparation error.
Add up your total purchases for that same week
Get all your supplier invoices from that week. Add up all ingredients: meat, fish, vegetables, dairy, dry goods. This is your total purchases. Calculate excluding VAT to compare fairly with your waste costs.
Calculate your waste percentage
Divide your total waste value by your total purchases and multiply by 100. For example: €280 waste on €2,100 purchases = (280/2100) × 100 = 13.3%. Repeat this for a few weeks to get an average.
✨ Pro tip
Measure your waste for 4 weeks in a row and calculate the average. One bad week could be coincidence, but a pattern over a month shows your true waste level.
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 count trim loss as waste?
Only unexpected trim loss. If you know a whole fish has 45% loss and you plan for it, it's not waste. It is waste: if the fish yields worse than expected due to poor quality.
How do I measure what guests leave on their plates?
That's difficult to measure exactly. Many restaurants estimate this at 2-5% of portion size. Focus first on the waste you can control: spoilage and overproduction in the kitchen.
Is 10% waste a lot for a restaurant?
That falls within the normal range of 5-15%. It depends on your kitchen type. Fine dining with lots of fresh products often has more waste than a bistro with more shelf-stable ingredients.
Can I prevent waste completely?
No, some waste is inevitable. Below 5% is almost impossible unless you buy very conservatively and then you'll miss out on sales. Between 5-10% is a realistic goal for most restaurants.
How often should I calculate my waste percentage?
Start with once a month to get a feel for it. If you see problems, you can measure weekly to see the impact of changes. Daily is too much effort for most kitchens.
📚 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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