Picture this: you decide to increase your salmon portion by 20 grams to wow customers, but three months later you're wondering why profits are shrinking. Most restaurant owners change portions without calculating the real impact on their food cost. Here's how to adjust portion sizes while protecting your bottom line.
Why adjusting portion sizes is risky
A tiny change in portion size can wreck your profit margins. Bump your steak portion from 200 to 250 grams? Your food cost jumps by 25%. With 100 portions per week, that's thousands of euros vanishing each year.
⚠️ Watch out:
Many kitchens adjust portions without updating the food cost. This makes your food cost look the same, but you're actually earning less per dish.
Calculate the impact before you start
Every adjustment needs math first. No exceptions. This prevents those nasty surprises that hit your bank account later.
💡 Example:
Your current salmon portion of 180 grams costs €6.30 (€35/kg). You want to go to 200 grams for a better guest experience.
- New portion: 200 grams
- New food cost: €7.00 per portion
- Difference: €0.70 per plate
Impact: €0.70 × 80 portions/week × 52 weeks = €2,912 per year
Three strategies to maintain food cost
You've got three solid options to protect your profitability:
- Increase selling price: Compensate higher costs with an adjusted menu price
- Adjust side dishes: Smaller portion of potatoes or vegetables
- Optimize ingredients: Cheaper alternatives for garnish
Option 1: Adjust your selling price
The most straightforward approach? Raise your menu price. Calculate exactly what you need to charge to maintain the same food cost percentage.
💡 Example calculation:
Current situation: €6.30 food cost on €22.00 = 28.6% food cost
- New food cost: €7.00
- Desired food cost: 28.6%
- New selling price: €7.00 ÷ 0.286 = €24.48
Price increase: €2.48 per dish
Option 2: Rebalance side dishes
Instead of hiking prices, keep total food cost steady by tweaking other components. From tracking this across dozens of restaurants, guests rarely notice these subtle shifts compared to outright price increases.
- Smaller portion of potatoes (from 200g to 150g)
- Less expensive vegetables as garnish
- Simpler sauce (less butter or cream)
💡 Practical example:
Extra salmon costs €0.70. Compensation through:
- Potatoes: 50g less = -€0.25
- Vegetables: simpler mix = -€0.30
- Sauce: less butter = -€0.15
Total savings: €0.70 - food cost stays the same
Option 3: Smart ingredient choices
Sometimes you can boost the experience without higher costs through smarter purchasing or prep techniques.
- Cheaper cut of fish with better preparation
- Seasonal vegetables instead of expensive imports
- Homemade sauces instead of ready-made
Test and measure the results
After every adjustment, monitor the results closely. Track your food cost per dish and gather guest feedback. Don't just hope it's working.
⚠️ Watch out:
Roll out changes gradually. Test on a few dishes first before adjusting your entire menu.
Digital support for portion adjustments
Manually calculating every scenario eats up valuable time. A food cost calculator automatically computes how portion changes affect your food cost and percentages.
How do you adjust portion sizes without losing food cost?
Calculate your current food cost per portion
Add up all ingredients from your current recipe. Note the exact quantities and calculate the total food cost per portion. This is your starting point for any adjustment.
Calculate the new food cost
Adjust the quantities to your desired new portion size. Calculate what this means for your total ingredient costs. Pay special attention to expensive ingredients like meat and fish.
Determine your compensation strategy
Choose between a price increase, adjusting side dishes, or smarter ingredient choices. Calculate for each option what it means for your food cost percentage.
Test the new portion in practice
Roll out the change on a limited number of dishes first. Monitor guest feedback and your actual food cost over a few weeks.
Evaluate and optimize
Check after a month whether your food cost percentage matches your calculation. Adjust if needed and roll out the change to other dishes.
✨ Pro tip
Test new portions during your slowest 2-hour service window first. Monitor exactly 15 plates to gauge prep time changes and customer reactions before rolling out permanently.
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 much can I increase my portion without raising the price?
This depends on your current food cost percentage. If you're at 28% now and want a maximum of 35%, you can increase your portion by about 25%. Always calculate this per dish.
Will guests notice if I make side dishes smaller?
Small adjustments (10-15%) usually go unnoticed, especially if you keep the presentation good. Larger changes (25%+) will be noticed.
Can I roll out portion adjustments gradually?
Yes, that's often smarter. Start with your best-selling dishes and monitor the effect. That way you learn what works before adjusting everything.
What if my new portion becomes too expensive for my target market?
Consider option 2 or 3 instead: adjusting side dishes or making smarter ingredient choices. You could also introduce a smaller premium portion alongside the standard option.
How often should I evaluate my portions?
Check this at least twice a year, or when ingredient prices change significantly. Also when you get complaints about portion size, it's time to evaluate.
Should I adjust portions differently for lunch versus dinner service?
Absolutely - lunch customers often prefer smaller, quicker portions while dinner guests expect heartier servings. Calculate food costs separately for each service to optimize both profit and customer satisfaction.
📚 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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