Picture this: you need just 2 kg of salmon for tonight's service, but your supplier demands a 5 kg minimum order. That extra 3 kg sits in your cooler, inflating your actual cost per dish. Here's how to calculate your true cost price and distribute those expenses fairly across your menu.
Why minimum order quantities mess with your cost price
Most suppliers enforce minimum order quantities. You need 2 kg of salmon, but you're stuck buying 5 kg. That extra 3 kg ends up in your cooler and drives up your real cost price per dish.
The issue: many restaurant owners only calculate what they use, not what they actually pay for. This makes their food cost look artificially low.
⚠️ Note:
Always calculate based on your actual purchase costs, not just what you directly use. Otherwise you'll underestimate your food cost.
Three calculation methods that actually work
You've got three options here, depending on your specific situation:
- Direct allocation: Push all costs through immediately
- Inventory method: Spread costs across expected future usage
- Waste calculation: Factor in expected spoilage losses
Method 1: Direct allocation
This approach passes all purchase costs straight to your current production. It gives you the most conservative (highest) cost price, but it's also the safest.
💡 Example:
You're making 20 portions of salmon fillet at 150g each = 3 kg needed.
- Required minimum order: 5 kg salmon at €22/kg
- Total purchase cost: €110
- Number of portions: 20
Cost price per portion: €110 ÷ 20 = €5.50
Go with this method if you're unlikely to use that extra salmon quickly or if you prefer being conservative with your numbers.
Method 2: Inventory method
Here you spread the costs across all products you can make from the purchase, including future portions. This is one of the most common blind spots in kitchen management - operators either don't track future usage or assume perfect turnover rates.
💡 Example:
Same scenario: 5 kg salmon for €110.
- Total possible portions: 5 kg ÷ 0.15 kg = 33 portions
- Cost price per portion: €110 ÷ 33 = €3.33
For your current 20 portions: 20 × €3.33 = €66.60
This method works well if you'll definitely use the salmon within its shelf life and don't expect significant spoilage.
Method 3: Calculate with waste costs
Sometimes you know upfront that some product will spoil. Then you calculate with expected loss built in.
💡 Example:
From your 5 kg salmon purchase, you expect to lose 1 kg to spoilage.
- Usable amount: 4 kg for 26 portions
- Cost price per portion: €110 ÷ 26 = €4.23
Current 20 portions cost: 20 × €4.23 = €84.60
Which method fits your operation?
Your choice depends on your specific circumstances:
- Direct allocation: For uncertain usage patterns or one-off purchases
- Inventory method: For regular demand and products with good shelf life
- Waste calculation: For items with short expiration dates or known spoilage rates
Impact on your menu pricing
These different cost prices create vastly different minimum selling prices at a 30% target food cost:
- Direct allocation: €5.50 ÷ 0.30 = €18.33 excl. VAT
- Inventory method: €3.33 ÷ 0.30 = €11.10 excl. VAT
- Waste calculation: €4.23 ÷ 0.30 = €14.10 excl. VAT
That's a €7 difference per dish. Choose deliberately which method matches your actual business operations.
How do you calculate cost price when forced to buy more?
Determine your actual need and minimum order quantity
Calculate how much you need for your planned production. Check with your supplier what the minimum order quantity is. The difference determines your 'excess' purchase.
Choose your calculation method
Direct allocation for uncertainty, inventory method for regular usage, waste costs for short shelf-life products. This choice determines your cost price per portion.
Calculate and document your cost price
Divide total purchase costs by the number of usable portions. Note which method you used for consistency in your cost price calculations.
✨ Pro tip
Track your waste percentages for 30 days on high-value ingredients with minimum orders. You'll discover that lamb typically spoils 15% faster than expected, while certain fish holds better than you thought.
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 always have to use the most expensive method (direct allocation)?
Not at all - pick the method that matches your real situation. For regular product usage with reliable turnover, the inventory method gives you a more accurate picture than charging everything to one production run.
What if I don't know how much I'll actually waste?
Start tracking your actual waste from these products for 3-4 weeks. You'll quickly see patterns emerge. Until you have that data, direct allocation keeps you on the safe side.
Can I pass these extra costs on to my customers?
Absolutely - adjust your menu prices to cover your real cost structure. Your customers are paying for your complete operation, including the constraints your suppliers impose on you.
Should I calculate this separately for every single product?
Focus on expensive ingredients like premium fish, meat, and specialty items where the impact matters. For cheaper staples, the inventory method usually works fine without significantly affecting your overall food cost.
📚 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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