Most restaurants unknowingly slash their profits by serving oversized portions without calculating the financial impact. Every extra gram of protein comes directly out of your bottom line. Here's how to determine the exact portion size that aligns with your pricing strategy.
What is break-even portion size?
Break-even portion size represents the exact weight in grams you must serve to achieve your target food cost percentage at a specific menu price. Serve less and your margins improve. Serve more and profits shrink.
💡 Example:
You sell steak for €28.00 (incl. 9% VAT) and want 30% food cost:
- Selling price excl. VAT: €28.00 ÷ 1.09 = €25.69
- Budget for meat: €25.69 × 0.30 = €7.71
- Beef costs €32/kg = €0.032/gram
Break-even portion: €7.71 ÷ €0.032 = 241 grams
Why precision matters
A seemingly minor 20-gram overage creates massive financial leakage. With beef at €32/kg, each extra 20 grams costs €0.64 per plate. Multiply that across 100 covers weekly? You're hemorrhaging €3,328 annually on just one dish.
This pattern we see repeatedly in restaurant financials - small portion inconsistencies that compound into substantial profit erosion over time.
⚠️ Heads up:
Always work with prices excluding VAT. That €28.00 menu price includes 9% VAT, making your actual selling price €25.69.
The break-even formula
The calculation is straightforward:
Break-even portion (grams) = (Selling price excl. VAT × Target food cost%) ÷ Price per gram
Follow these steps:
- Strip out VAT from your menu price
- Multiply by your desired food cost percentage
- Divide by the ingredient's cost per gram
💡 Salmon example:
Salmon fillet for €24.00 (incl. VAT), targeting 32% food cost:
- Selling price excl. VAT: €24.00 ÷ 1.09 = €22.02
- Budget for salmon: €22.02 × 0.32 = €7.05
- Salmon costs €28/kg = €0.028/gram
Break-even portion: €7.05 ÷ €0.028 = 252 grams
Working backwards: portion to price
Sometimes you'll want to maintain a specific portion size and calculate the required menu price instead. Simply reverse the formula:
Minimum selling price excl. VAT = (Portion weight × Price per gram) ÷ Target food cost%
💡 Chicken example:
You want 200 grams of chicken breast, chicken costs €12/kg, targeting 28% food cost:
- 200 grams × €0.012 = €2.40 ingredient cost
- Minimum price excl. VAT: €2.40 ÷ 0.28 = €8.57
- Including 9% VAT: €8.57 × 1.09 = €9.34
Minimum menu price: €9.34
Factoring in trim loss
Products with significant trim loss require adjusted calculations. You can't use the raw purchase price - you need the actual usable yield cost.
⚠️ Heads up:
Whole fish with 45% trim loss gives you 55% yield. A €18/kg purchase price becomes €18 ÷ 0.55 = €32.73/kg for usable fillet.
Executing consistent portion control
Calculating break-even portions means nothing without proper execution. Here's how to maintain consistency:
- Keep digital scales accessible and weigh portions during prep
- Post portion guidelines with actual weights at each station
- Conduct weekly spot checks on plated portions
- Recalculate immediately when supplier prices change
Food cost management tools can automatically track your break-even portions and flag when actual costs drift above targets due to oversized servings.
How do you calculate break-even portion size? (step by step)
Calculate your selling price excluding VAT
Divide your menu price by 1.09 (at 9% VAT). A dish of €28.00 becomes €28.00 ÷ 1.09 = €25.69 excl. VAT. This is your actual selling price for the calculation.
Determine your budget for the main ingredient
Multiply your selling price excl. VAT by your desired food cost percentage. At €25.69 and 30% food cost you get €25.69 × 0.30 = €7.71 budget for the meat.
Divide by the price per gram
Divide your budget by the kilo price of the ingredient (divided by 1000 for price per gram). With beef at €32/kg that's €0.032/gram. €7.71 ÷ €0.032 = 241 grams break-even portion.
✨ Pro tip
Audit your 5 highest-volume dishes for break-even portion accuracy within the next 48 hours. These items typically represent 60-80% of your total protein costs.
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 calculate break-even for every ingredient on the plate?
No, focus on your primary protein - the most expensive component. Calculate vegetables, starches, and sauces separately as part of your overall food cost analysis.
How do I handle supplier price increases mid-month?
Recalculate immediately and decide: reduce portion size or raise menu prices. A 10% ingredient cost increase means your 200-gram portion effectively becomes 182 grams to maintain the same food cost percentage.
What's the best way to verify my team is hitting portion targets?
Randomly weigh finished plates during service and photograph correct portions as kitchen references. Weekly food cost variance reports will quickly reveal if portions are creeping up beyond your calculations.
📚 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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