A difference of 20 grams per portion seems small, but it adds up quickly. With 100 covers per day you're already losing €600-1200 per month, depending on the ingredient...
Most restaurateurs think 20 grams extra per portion won't hurt their bottom line—they're wrong. With 100 covers daily, you're bleeding €600-1200 monthly depending on the ingredient. Here's exactly how to calculate what those "generous" portions actually cost you.
The formula for euro loss per month
Calculating your monthly loss from a portion difference is straightforward:
Monthly loss = Extra grams × Price per gram × Portions per day × Working days
You need three pieces of data: the price per gram of the ingredient, daily portion count, and monthly operating days.
💡 Example: 20 grams extra salmon
Your chef serves 170 grams of salmon instead of 150 grams per portion:
- Salmon price: €28/kg = €0.028 per gram
- Extra per portion: 20 grams × €0.028 = €0.56
- Portions per day: 80
- Working days per month: 26
- Monthly loss: €0.56 × 80 × 26 = €1,164
Different ingredients, different impact
The damage varies dramatically by ingredient type. Premium proteins hurt way more than vegetables or starches.
💡 Example: Comparison of different ingredients
20 grams extra per portion, 100 portions/day, 26 working days:
- Beef steak (€45/kg): €468 per month
- Salmon (€28/kg): €292 per month
- Chicken (€12/kg): €125 per month
- Pasta (€3/kg): €31 per month
Even cheap ingredients drain tens of euros monthly.
The number of portions determines the damage
Higher volume means higher losses. A small bistro with 50 covers suffers less than a packed restaurant pushing 150 covers.
- 50 portions/day: €0.56 × 50 × 26 = €728 per month
- 100 portions/day: €0.56 × 100 × 26 = €1,456 per month
- 150 portions/day: €0.56 × 150 × 26 = €2,184 per month
⚠️ Note: Count weekends if you're open. Many owners forget Friday and Saturday—that's 8-10 extra working days monthly.
The annual loss: a frightening picture
Convert monthly figures to yearly totals and the impact hits hard. That salmon example of €1,164 monthly equals €13,968 annually in lost profit—from just 20 grams extra salmon per portion.
For restaurants with multiple dishes experiencing portion drift, losses can reach €30,000-50,000 yearly. That's enough to hire another chef or boost profit margins significantly.
Why this happens so often
Portion inconsistencies stem from unclear kitchen standards—the kind of thing you only learn after closing your first month at a loss. Without precise portion guidelines, each cook wings it differently.
- No scale: Cooks eyeball portions
- Different cooks: Everyone interprets "normal" differently
- Rush periods: Stress leads to generous portions
- Zero oversight: Nobody verifies portion accuracy
💡 Example: Impact of different cooks
Three cooks, same dish, different portions:
- Cook A: 150 grams (recipe standard)
- Cook B: 170 grams (+20 grams)
- Cook C: 180 grams (+30 grams)
If cooks B and C handle 60% of services, this single dish costs €800+ monthly in overages.
Real-world example: Restaurant De Smaakmaker
Restaurant De Smaakmaker serves 120 portions daily, operating 28 days monthly. They struggled with portion control across three popular dishes:
Situation before improvement:
- Beef stroganoff: 25 grams extra beef (€32/kg) = €0.80 × 40 portions × 28 = €896/month
- Grilled sea bream: 30 grams extra fish (€24/kg) = €0.72 × 35 portions × 28 = €705/month
- Pasta carbonara: 15 grams extra bacon (€18/kg) = €0.27 × 45 portions × 28 = €340/month
Total monthly loss: €1,941
Annual loss: €23,292
After implementing portion control, losses dropped 85%, saving nearly €20,000 annually.
Common mistakes
1. Only controlling expensive ingredients
Many restaurants monitor meat and fish but ignore cheaper ingredients. But 50 grams extra potatoes per portion costs €65 monthly at 150 portions daily.
2. Not counting weekends
Weekends often generate 30-40% of monthly revenue. Skip these days in calculations and you're underestimating losses significantly.
3. Ignoring seasonal variations
Ingredient prices fluctuate seasonally. Recalculate losses quarterly using current purchase prices for accurate assessments.
4. Overlooking side dishes
Focus usually goes to main ingredients, but sauces, vegetables, and garnishes collectively create substantial additional losses.
5. Not standardizing serving spoons
Different spoon sizes create portion variations. Use standardized kitchen tools for each dish.
How to prevent this
Solutions require clear standards and consistent monitoring. Everyone must know exact portion specifications.
- Weigh portions: Use scales, not estimates
- Document everything: Record portion sizes in recipes
- Train your team: Ensure everyone uses identical measurements
- Regular audits: Verify portions stay accurate over time
The psychological side
Cooks often give extra portions thinking it boosts customer satisfaction. However, research shows guests value consistency more. A reliable 150-gram portion scores higher than portions varying between 150-180 grams.
Tools like tools like KitchenNmbrs can help track these variations and calculate exact losses automatically.
Bottom line
Just 20 grams extra per portion can cost thousands annually. Impact depends on three variables: ingredient price per gram, daily portion volume, and monthly operating days. Use the formula Monthly loss = Extra grams × Price per gram × Portions per day × Working days to calculate your specific losses. Prevention requires clear procedures, team training, and regular portion verification.
How do you calculate the euro loss? (step by step)
Calculate the price per gram
Divide the kilogram price of the ingredient by 1000. With salmon at €28/kg that becomes €28 ÷ 1000 = €0.028 per gram. Always check your latest invoice for the current purchase price.
Determine the extra loss per portion
Multiply the extra grams by the price per gram. With 20 grams extra salmon: 20 × €0.028 = €0.56 loss per portion. This seems small, but it adds up quickly.
Calculate how many portions you serve per month
Multiply your average portions per day by the number of working days per month. At 100 portions/day and 26 working days: 100 × 26 = 2,600 portions per month of this dish.
Calculate the total monthly loss
Multiply the loss per portion by the number of portions per month. €0.56 × 2,600 = €1,456 loss per month. This is the amount you can save directly by standardizing portions.
✨ Pro tip
Track your 3 most expensive proteins by weighing every 10th portion during peak service for 2 weeks straight. This 30-second check per dish can reveal €500+ monthly in hidden losses.
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
How do I know if my portions are consistently oversized?
Weigh every portion of your top 5 dishes for one full week. Compare results against your recipe specifications. Any variation exceeding 10% likely costs you money.
What's the fastest way to standardize portion sizes across different shifts?
Use portion control tools like standardized ladles, scoops, and measuring cups for each dish. Label them clearly and train each shift separately. Make it impossible to guess portion sizes.
Should I factor in waste when calculating these losses?
Absolutely. Add 5-8% to your calculated losses to account for prep waste, dropped plates, and remakes. These hidden costs compound your portion control problems significantly.
📚 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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