An ingredient you use in multiple dishes has one purchase price but different allocations per dish. Many entrepreneurs make mistakes by dividing the total purchase price by the number of dishes, but that's incorrect if the portions differ. You need to calculate per dish how many grams you use and what that costs.
Why this matters
Say you buy 5 kg of beef for €90. You use this meat for steak (200g), stew (150g), and carpaccio (80g). The purchase price is €18/kg, but each portion costs differently:
- Steak: 200g × €18/kg = €3.60 per portion
- Stew: 150g × €18/kg = €2.70 per portion
- Carpaccio: 80g × €18/kg = €1.44 per portion
If you don't track this properly, you won't know which dish is most profitable.
💡 Example:
You buy salmon for €24/kg and use it in 3 dishes:
- Salmon fillet: 180g = €4.32 per portion
- Salmon salad: 120g = €2.88 per portion
- Salmon tartare: 100g = €2.40 per portion
Same product, but different cost prices per dish.
The correct calculation formula
For each dish where you use the ingredient:
Cost price per portion = (Portion weight in grams / 1000) × Purchase price per kg
This formula applies to all ingredients you use in multiple dishes: meat, fish, vegetables, herbs, oils.
⚠️ Note:
Don't forget to factor in cutting loss. If you have 20% loss when filleting fish, your actual price per kilo goes up: €24/kg becomes €24/0.80 = €30/kg for the fillets.
How to organize this
Make a list of all ingredients you use in multiple dishes. For each ingredient, note:
- Purchase price per kg (including any cutting loss)
- Which dishes you use it in
- How many grams per portion in each dish
- Cost price per portion per dish
💡 Practical example:
Mushrooms €8/kg, used in:
- Risotto: 80g = €0.64 per portion
- Omelet: 60g = €0.48 per portion
- Salad: 40g = €0.32 per portion
- Pasta: 70g = €0.56 per portion
This way you see exactly what each dish costs in mushrooms.
Digital vs. manual tracking
Many kitchens do this with Excel, but it quickly becomes messy. If your supplier raises the price, you have to manually update all dishes. A system like KitchenNmbrs automatically calculates the new cost price for all dishes as soon as you adjust the purchase price.
The advantage: you immediately see which dishes become too expensive and where you need to adjust your prices.
How do you calculate the cost price per dish? (step by step)
Determine the actual purchase price per kg
Take the price you pay and factor in any cutting loss if applicable. With 20% loss: divide by 0.80. With whole fish that you fillet: calculate based on the fillet price, not the price of the whole fish.
Measure the exact portion size per dish
Weigh how many grams of this ingredient you use in each dish. Do this for a few portions and take the average. Be precise — 10 grams difference can matter a lot.
Calculate the cost price per portion per dish
Use the formula: (grams per portion / 1000) × price per kg. Do this for each dish where you use the ingredient. Update this calculation every time your supplier raises the price.
✨ Pro tip
Check your 5 most expensive ingredients that you use in multiple dishes. If you track those properly, you have 80% of your cost price under control.
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 do this for all ingredients?
Start with the most expensive ingredients you use in multiple dishes: meat, fish, premium vegetables. These have the biggest impact on your cost price. Salt and pepper you can do later.
How often should I update the prices?
Check at least once a month whether your suppliers have raised prices. With major price increases (>10%), you need to immediately recalculate your cost prices to see if your menu price still works.
What if I have different suppliers for the same product?
Calculate based on the price of the supplier you use most. Or make a weighted average if, for example, you buy 70% from supplier A and 30% from supplier B.
How do I handle seasonal products that vary greatly in price?
Calculate based on the average price over the year, or adjust your cost price per season. Asparagus in May costs differently than in March. Then also update your food cost calculation.
Can't I just estimate this?
Estimating leads to errors of 20-30%. With an ingredient costing €2 per portion, that means €0.40-€0.60 difference. Over a year that can cost hundreds of euros in lost profit.
📚 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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