I'll admit it - most chefs develop new dishes based on gut feeling rather than cold, hard numbers. But your gut doesn't pay the bills. Here's exactly how to calculate whether that exciting new dish will actually improve your margins.
Why you need to know your current average margin
You can't compare anything without a baseline. Your average margin isn't just adding up percentages - it's weighted by actual sales volume.
💡 Example of current situation:
Restaurant with 5 main courses:
- Steak: 30% food cost, 40 sold/week
- Salmon: 28% food cost, 35 sold/week
- Pasta: 25% food cost, 60 sold/week
- Chicken: 32% food cost, 25 sold/week
- Vegetarian: 22% food cost, 15 sold/week
Weighted average: 27.7% food cost
The formula for weighted average food cost
Simple math here. Don't just average the percentages - that's misleading:
Weighted average = (Food cost1 × Sales1 + Food cost2 × Sales2...) / Total sales
This shows what you're actually earning across your entire menu mix.
Calculate your new dish
Three numbers tell the whole story:
- Ingredient cost per portion - everything, down to the last herb
- Expected selling price - be realistic about your market
- Expected sales per week - conservative estimates work better
💡 Example of new dish:
New truffle pasta:
- Ingredient cost: €6.80
- Selling price: €26.50 incl. VAT (€24.31 excl.)
- Expected sales: 20 portions/week
Food cost: (€6.80 / €24.31) × 100 = 28.0%
Calculate the impact on your total margin
Now comes the real test. Add this dish to your current mix and recalculate your weighted average. This is a pattern we see repeatedly in restaurant financials - dishes that look good in isolation can hurt your overall margins.
⚠️ Watch out:
A new dish can worsen your average, even if it has lower food cost than your worst performer. Volume matters more than you think.
Scenario analysis: what if it becomes a hit?
Run multiple scenarios before you commit:
- Conservative: 15 portions/week
- Realistic: 25 portions/week
- Optimistic: 40 portions/week
Each scenario shows different margin impacts. You'll see exactly where your break-even point lies.
💡 Example of impact:
At 20 portions of truffle pasta per week:
- Old situation: 27.7% average food cost
- New situation: 27.8% average food cost
- Impact: 0.1 percentage point worse
At €300,000 annual turnover this costs you an extra €300 per year.
When is a new dish worth it?
A new dish earns its place if:
- It improves your average food cost (even 0.5% helps)
- It can replace a poor performer
- It drives high volume at reasonable margins
- It completes your menu without significant cost impact
Sometimes a 30% food cost dish that flies off the table beats a 25% dish that sits there. Volume and velocity matter. Tools like a food cost calculator can help you run these numbers quickly.
How do you calculate if a new dish scores better? (step by step)
Calculate your current weighted average food cost
Multiply the food cost of each dish by the number of portions sold per week. Add all results together and divide by your total sales. This is your benchmark.
Calculate the food cost of your new dish
Add up all ingredient costs (including garnish and sauces). Divide this by your selling price excluding VAT and multiply by 100 for the percentage.
Calculate the new weighted average
Add your new dish to the calculation with a realistic sales estimate. Compare the new weighted average with your current situation to see the impact.
✨ Pro tip
Run your numbers on 3 different weekly sales volumes before launching any new dish. Most restaurants see 40% lower sales than their initial optimistic projections.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
Was this article helpful?
Frequently asked questions
Should I always reject dishes with higher food costs than my current average?
Not necessarily. A dish with 35% food cost that sells 50 portions weekly can improve your overall margins better than a 25% dish that moves only 10 portions. Volume changes everything.
How do I predict realistic sales volumes for untested dishes?
Look at your current menu's similar items and price points. Conservative estimates protect you from disappointment. Consider running it as a weekend special first to gauge real demand.
What's the minimum margin improvement that justifies menu changes?
Even 0.3-0.5 percentage points matter at scale. On €400,000 annual revenue, that's €1,200-€2,000 extra profit. Factor in the cost of menu reprints and staff training though.
📚 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.
Develop recipes with instant cost calculation
Every new recipe has a cost price. KitchenNmbrs calculates it while you build the recipe — so you know if it's profitable before it hits the menu. Try it free.
Start free trial →