Most restaurants assume smaller portions automatically mean higher profits – they're dead wrong. Operators routinely offer different portion sizes without running the numbers first. The math reveals which portions actually boost your bottom line.
Why calculating portion size matters
Offering small and large portions seems obvious: more choice for guests, more revenue for you. But the reality hits differently. Many restaurants calculate incorrectly and lose money on their small portions.
The main pitfalls:
- Small portion gets priced too low (not proportional)
- Fixed costs (service, dishwashing) stay the same
- Guests often pick the cheaper option
- Kitchen handles more complexity with different portions
The cost price calculation for different portions
You calculate the cost price separately for each portion size. Not all costs scale with portion size – something most kitchen managers discover too late after rolling out multiple portions across their menu.
💡 Example:
Pasta carbonara - regular portion €16.50 (incl. 9% VAT):
- Pasta: 120g = €0.60
- Bacon: 40g = €1.20
- Egg + cream: €0.80
- Cheese + herbs: €0.70
- Garnish: €0.20
Total ingredient costs: €3.50
For a small portion (80% of the quantity), ingredient costs become:
- Pasta: 96g = €0.48
- Bacon: 32g = €0.96
- Egg + cream: €0.64
- Cheese + herbs: €0.56
- Garnish: €0.20 (stays the same!)
Total small portion: €2.84
Fixed costs that don't scale
Certain costs stay the same, no matter what portion size you serve:
⚠️ Note:
Garnish, sauces, plate, service and dishwashing cost the same for small and large portions. Build this into your cost price.
Fixed costs per plate (regardless of portion size):
- Garnish and decoration: €0.20
- Bread beforehand: €0.30
- Service (time): €2.50
- Dishwashing and energy: €0.40
- Overhead per plate: €1.20
Total fixed costs: €4.60 per plate
The financial analysis: is it profitable?
Now you calculate if both portions make money:
💡 Example calculation:
Regular portion - €16.50 (€15.14 excl. VAT):
- Ingredients: €3.50
- Fixed costs: €4.60
- Total costs: €8.10
- Profit: €15.14 - €8.10 = €7.04
- Profit margin: 46.5%
💡 Small portion - €13.50 (€12.39 excl. VAT):
- Ingredients: €2.84
- Fixed costs: €4.60 (same!)
- Total costs: €7.44
- Profit: €12.39 - €7.44 = €4.95
- Profit margin: 40.0%
Guest choice behavior changes everything
Offering a small portion shifts guest behavior. Many guests pick the cheaper option, even if they would've ordered the regular portion otherwise.
Say you normally sell 100 pastas per week at €16.50. With small portions, this becomes:
- 60 small portions at €13.50 = €810
- 40 regular portions at €16.50 = €660
- Total revenue: €1,470 (was €1,650)
⚠️ Note:
Your revenue drops by €180 per week, but your profit per plate stays reasonable. Always check both effects.
Multiple portions work financially when
Different sizes make sense if:
- You attract extra guests who wouldn't come otherwise
- Small portion maintains at least 35% profit margin
- You can upsell (appetizer, dessert, drinks)
- Fixed costs are low (like with delivery)
Systems that make portion calculations easier
A food cost calculator automatically computes cost price per portion size. You instantly see which portions are profitable and can test different scenarios.
These systems also track sales figures per portion, so you can monitor if your revenue increases or decreases by offering different sizes.
How do you calculate whether different portions are beneficial? (step by step)
Calculate cost price regular portion
Add up all ingredient costs for your standard portion. Don't forget garnish, sauces or oil. Divide by your selling price excl. VAT to get your current food cost percentage.
Determine small portion costs
Calculate 70-80% of the variable ingredients (meat, fish, vegetables). Keep fixed costs the same: garnish, sauces, service and dishwashing cost the same per plate.
Set prices and check margins
Calculate what price you need for at least 35% profit margin on both portions. Check whether this is realistic for your target audience and concept.
Test and measure results
Roll out both portions for 4-6 weeks. Measure total revenue, number of portions sold per type and average check value. Adjust if needed.
✨ Pro tip
Track your top 3 dishes for exactly 6 weeks after introducing small portions. Measure total table spend, not just individual dish revenue – guests might order appetizers or desserts with smaller mains.
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 cheaper should a small portion be?
No more than 15-20% cheaper than the regular portion. Otherwise the difference in cost price becomes too small to stay profitable.
Which costs stay the same for different portions?
Service, dishwashing, garnish, sauces, bread and overhead costs are identical per plate. Only main ingredients scale with portion size.
What if everyone picks the small portion?
Then you lose revenue without proportional cost savings. Test first with a few dishes and measure the impact on total revenue.
How do I stop guests from always choosing the cheaper option?
Position the regular portion as 'recommended' and don't make the price gap too wide. A maximum of €3-4 difference usually works well.
Should I also offer large portions?
Large portions are often more profitable since fixed costs stay the same but you can charge more. Test this if small portions succeed.
What's the minimum profit margin for small portions?
Keep small portions above 35% profit margin. Below this threshold, the operational complexity isn't worth the financial return.
📚 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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