The cost price of an ingredient is determined by the price at the moment of use, not purchase. Many entrepreneurs make the mistake of calculating with the old purchase price, while the actual cost price can be higher due to spoilage, weight loss or price fluctuations. In this article you'll learn how to calculate the real cost price of ingredients you buy today but use later.
Why purchase price is not the same as cost price
If you buy meat today for €12/kg and use it next week, your actual cost price is often higher than €12/kg. This is because of:
- Weight loss: Meat loses moisture during storage (2-5%)
- Cutting loss: During processing, fat, tendons or bone are removed
- Spoilage: Part of it may become unusable
- Energy costs: Cooling and storage cost money
💡 Example:
You buy 10 kg of beef for €12/kg = €120 total
- After 1 week of storage: 9.7 kg (3% weight loss)
- After processing: 8.2 kg usable meat (15% cutting loss)
- Cooling energy costs: €2
Actual cost price: (€120 + €2) / 8.2 kg = €14.88/kg
Calculation with inventory turnover
For a correct cost price, you need to calculate with your average inventory turnover. This is the time between purchase and use of ingredients.
Formula for actual cost price:
Cost price = (Purchase price + Storage costs) / (Purchase weight × Yield%)
⚠️ Note:
Always calculate with the yield after storage and processing. Many entrepreneurs forget the weight loss during storage.
Including storage costs
Storage costs consist of:
- Energy costs: Cooling/freezing (average €0.15-0.25 per kg per week)
- Packaging material: Vacuum bags, containers (€0.05-0.10 per kg)
- Labor: Time for storage and inspection
- Spoilage risk: 1-3% of the value as a buffer
💡 Example calculation:
Salmon fillet €18/kg, 1 week storage:
- Purchase price: €18.00/kg
- Cooling 1 week: €0.20/kg
- Weight loss: 2%
- Spoilage risk: 1% of value = €0.18/kg
Cost price: (€18.00 + €0.20 + €0.18) / 0.98 = €18.76/kg
Inventory valuation methods
There are different ways to value your inventory:
- FIFO (First In, First Out): Use oldest inventory first
- Average cost price: Average all purchases over time
- LIFO (Last In, First Out): Use newest inventory first (less common)
For most restaurants, FIFO makes the most sense because it prevents spoilage.
Digital inventory registration
Keeping track of actual cost prices becomes much easier with a digital system. Apps like KitchenNmbrs can automatically calculate storage costs and yield percentages, so you always have the correct cost price for your recipes.
How do you calculate the actual cost price? (step by step)
Register purchase data
Note the purchase price, weight and purchase date of each product. Also keep the invoice for verification.
Measure weight loss and yield
Weigh the product again just before use. Calculate the yield after processing (usable weight divided by original weight).
Add storage costs
Calculate energy costs (€0.15-0.25 per kg per week), packaging and a small buffer for spoilage to the purchase price.
Calculate actual cost price
Divide the total costs (purchase + storage) by the actual usable weight. This is your cost price for recipe calculations.
✨ Pro tip
Keep a log of yield percentages per supplier. Some suppliers consistently have higher or lower yield, which can influence your purchasing decisions.
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
Do I always need to include storage costs in my cost price?
Yes, especially for products you store longer than 3 days. For fresh products you use within 24 hours, you can often ignore storage costs.
How do I calculate energy costs for cooling?
Calculate an average of €0.15-0.25 per kg per week for cooling, depending on your energy rate. For freezing this is €0.10-0.20 per kg per week.
What if I buy large quantities for better prices?
Then calculate the total costs including extra storage, weight loss and spoilage risk. Sometimes a smaller purchase at a slightly higher price is more cost-effective.
How often should I update my cost prices?
Check your cost prices at least monthly, especially for your best-selling dishes. Update more frequently if there are major price fluctuations from suppliers.
Can I automate this instead of calculating manually?
Yes, systems like KitchenNmbrs can automatically calculate storage costs and yield percentages per ingredient type.
📚 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.
Optimize your purchasing with data
Know exactly which supplier is most cost-effective and how price changes affect your margins. KitchenNmbrs links purchasing directly to recipe costs. Try it free for 14 days.
Start free trial →