Ingredients that are on your menu purely based on availability require a different way of calculating margin. You don't know in advance what you'll buy and at what price. Yet you need to ensure every dish remains profitable, even with changing ingredients.
The problem with seasonal ingredients
Many restaurants work with seasonal menus or specials that depend on what the supplier offers. The price of asparagus in March is different from May. Wild mushrooms cost something different every week. And yet you need to set a menu price before you know exactly what you'll be paying.
💡 Example:
You make a 'fish of the day' dish. This week your supplier has:
- Sea bass: €28/kg
- Dorade: €24/kg
- Cod: €18/kg
What price do you put on the menu? And how do you know if you're making a profit?
The worst-case method
The safest way is to calculate with the most expensive ingredient you could use. That way you know for sure you'll always make a profit, no matter what you buy.
Formula:
- Determine the most expensive ingredient from your selection
- Calculate cost price with this ingredient
- Add desired margin
- This becomes your fixed menu price
💡 Example calculation:
Fish of the day (200g portion):
- Most expensive fish: €28/kg = €5.60 per portion
- Garnish and sauce: €2.40
- Total cost price: €8.00
At 30% food cost: €8.00 ÷ 0.30 = €26.67 excl. VAT
Menu price: €29.10 incl. 9% VAT
The average-price method
Another approach is to work with an average purchase price. You look at what you paid on average for similar ingredients over the past months and calculate with that.
⚠️ Heads up:
This method is riskier. If prices rise or you buy expensive ingredients more often, you'll fall behind the facts.
Flexible portion size
A clever trick is to adjust your portion size to the purchase price. With expensive ingredient you give a smaller portion, with cheap ingredient a more generous portion. That way your cost price stays stable.
💡 Example flexible portion:
You want €6.00 of fish per plate:
- Sea bass €28/kg → 215g portion
- Dorade €24/kg → 250g portion
- Cod €18/kg → 330g portion
Cost price stays €6.00, guest always gets a full portion
Weekly price check
With seasonal ingredients you need to check your numbers more often. What was profitable last week could be a loss this week. Plan a moment each week to compare your current purchase prices with your menu price.
Many restaurants use an app like KitchenNmbrs to keep track of their ingredient prices and quickly see if their margin still works with changing purchase prices.
How do you calculate margin with changing ingredients?
Gather all possible purchase prices
Make a list of all ingredients you could use with their current prices. Also ask your supplier about expected price fluctuations.
Choose your calculation method
Decide whether you calculate with the most expensive option (safe), average price (risky), or flexible portions (smart but more work).
Calculate your minimum menu price
Use your chosen method to calculate the cost price. Divide by your desired food cost percentage to get your minimum selling price.
Check your actual margin weekly
Compare your actual purchase prices with your menu price each week. Adjust if your margin gets too low.
✨ Pro tip
Make agreements with your supplier about maximum prices. For example: 'I can pay up to €25/kg for fish, above that you call me first.' That way you avoid unpleasant surprises.
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 need to adjust my menu price every week to the purchase price?
That depends on your concept. Restaurants with daily specials can do this, but a fixed menu can't. Work with a safe margin that absorbs fluctuations.
What if I can't get an ingredient?
Always have a backup ingredient in the same price range. Communicate transparently to guests that these are seasonal products that may change.
How do I know if my margin still works?
Check your actual purchase prices against your menu price at least weekly. If your food cost goes above 35%, it's time to adjust.
Can I charge different prices for different ingredients?
Yes, but communicate this clearly. 'Fish of the day - market price' or 'from €24' are honest ways to pass on price differences.
What's a safe margin for seasonal ingredients?
Calculate with at least 10-15% extra margin on top of your normal food cost to absorb price fluctuations. So if you normally calculate 30%, go to 25% for seasonal products.
⚠️ EU Regulation 1169/2011 — Allergen Information — https://eur-lex.europa.eu/eli/reg/2011/1169/oj
The allergen information on this page is based on EU Regulation 1169/2011. Recipes and ingredients may vary by supplier. Always verify current allergen information with your supplier and communicate this correctly to your guests. KitchenNmbrs is not liable for allergic reactions.
In the UK, the FSA enforces allergen regulations under the Food Information Regulations 2014.
📚 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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