📝 Inventory management & stock control · ⏱️ 3 min read

How do I calculate the cost of wasted food per month?

📝 KitchenNmbrs · updated 06 Apr 2026

Quick answer
Most restaurant owners think they waste about 5% of their food purchases - but that's wishful thinking. The harsh reality? You're probably throwing away 10-15% of what you buy. That seemingly small difference can cost thousands each month.

Most restaurant owners think they waste about 5% of their food purchases - but that's wishful thinking. The harsh reality? You're probably throwing away 10-15% of what you buy. That seemingly small difference can cost thousands each month.

What counts as wasted food?

It's not just what hits the trash bin. These costs add up fast:

  • Spoiled products from improper storage
  • Too much prepared food that doesn't sell
  • Mise-en-place that sits too long and goes bad
  • Products past their expiration date
  • Cutting waste that's larger than normal

⚠️ Note:

Count only the purchase value, not the potential selling value. You threw away €5 worth of vegetables, not €20 worth of potential salad.

The three categories of waste

Breaking waste into categories helps you spot patterns:

  • Pre-prep waste: Products that spoil before you use them
  • Prep waste: Too much prepared, poor portioning
  • Service waste: Dishes that come back to the kitchen

? Example calculation:

Restaurant with €8,000 purchases per month:

  • Pre-prep waste: €320 (4%)
  • Prep waste: €240 (3%)
  • Service waste: €160 (2%)

Total waste: €720 per month (9%)

How do you measure this in practice?

Don't try weighing everything at once - you'll burn out. Start simple:

  • Week 1: Count only meat and fish (most expensive products)
  • Week 2: Add vegetables and dairy
  • Week 3: Count everything, including small items
  • Week 4: Repeat week 3 for reliability

After managing kitchen operations for nearly a decade, I've seen this gradual approach work better than trying to track everything from day one.

? Practical example:

Bistro with 80 covers per day measures 1 week:

  • Monday: €45 wasted (quiet day)
  • Tuesday: €32 wasted
  • Wednesday: €28 wasted
  • Thursday: €55 wasted (overestimated)
  • Friday: €38 wasted
  • Saturday: €42 wasted

Weekly average: €40 per day × 26 days = €1,040 per month

From daily figures to monthly total

Use this simple formula:

Monthly waste = (Average per day × Working days per month)

Most restaurants work 26 days monthly (6 days weekly). Seven-day operations? Use 30 working days.

⚠️ Note:

Measure for at least 2 weeks. One week might be unusually high or low due to events, delivery problems, or staff issues.

What is normal waste?

Industry benchmarks for waste percentages:

  • Excellent: 3-5% of total purchases
  • Good: 5-8% of total purchases
  • Average: 8-12% of total purchases
  • Problematic: 12%+ of total purchases

Hitting 12% or higher? You're hemorrhaging money through poor planning or oversized portions.

? Impact calculation:

Restaurant with €10,000 purchases per month:

  • At 15% waste: €1,500 per month wasted
  • At 8% waste: €800 per month wasted
  • Difference: €700 per month = €8,400 per year

Improvement of 7 percentage points saves €8,400 per year

Digital tracking vs. paper

Paper tracking has serious flaws:

  • Lists get lost
  • No overview of trends
  • Difficult to look back
  • No automatic calculations

Digital tools like KitchenNmbrs track waste automatically and calculate monthly costs instantly. You'll spot trends faster and adjust quicker.

How do you calculate waste costs per month? (step by step)

1

Measure everything you throw away for one week

Place a scale by the trash bin and note each day what you throw away with the purchase price. Also include spoiled products and too much prepared mise-en-place.

2

Calculate your average per day

Add up all the wasted amounts from the week and divide by 6 (or 7 if you're open seven days). This gives you your average waste per working day.

3

Multiply by working days per month

Take your daily average times 26 working days (6 days per week) or 30 working days (7 days per week). This gives you your total waste costs per month.

✨ Pro tip

Track waste for exactly 14 consecutive days, including weekends. Most kitchens see 40% higher waste on Sundays and Mondays due to weekend prep miscalculations.

Calculate this yourself?

In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.

Try KitchenNmbrs free →

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Frequently asked questions

Should I also count cutting waste in my waste calculation?
Only if your cutting waste exceeds normal ranges. Standard cutting waste (15-25% for meat, 40-55% for fish) belongs in your cost price calculation, not waste tracking.
What if my waste consistently hits 15% or higher?
Focus on your top 3 wasted items first - they usually account for 70% of total waste. Check portion sizes, prep quantities, and FIFO rotation. Small changes to these items create massive savings.
Can I estimate waste without weighing everything?
Rough estimates work for initial assessment, but real control needs exact figures. Start with your priciest ingredients (meat, fish) if full tracking feels overwhelming. Build the habit gradually.
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

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.

JS

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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