A pantry full of slow-moving products costs you money. Every day a product sits longer than necessary, you lose profit. Here's why this happens and how to get your inventory turning over faster.
Why products sit around
Most kitchens have the same problem: they buy based on gut feeling, not data. You see a nice fish at the supplier and think: "I'll take that." But you don't actually know how much you sell.
💡 Example:
You buy 5 kg of dorade every week because "that's about right". But you sell an average of just 3.5 kg:
- Purchase: 5 kg × €18/kg = €90
- Sales: 3.5 kg × €32/kg = €112
- Loss: 1.5 kg × €18/kg = €27 per week
Annual loss: €27 × 52 = €1,404
The real cost of slow inventory turnover
Products that sit around cost more than just the product itself. You also pay for:
- Cooling costs: Energy to keep everything cold
- Quality loss: Products become less fresh
- Waste: What you throw away is 100% loss
- Cashflow: Your money is tied up in inventory
⚠️ Heads up:
A product sitting in your cooler for 2 weeks costs you more than just the purchase price. Factor in at least 20% extra costs from quality loss and energy.
How to measure inventory turnover
The formula for inventory turnover is straightforward:
Inventory Turnover = Monthly Purchases / Average Inventory
💡 Example calculation:
You buy €3,000 in vegetables per month. Your average inventory is €500:
- Inventory turnover: €3,000 / €500 = 6
- This means: your inventory turns 6× per month
- In other words: fresh inventory every 5 days
For fresh products, 6-8× per month is normal.
Signs you're buying too much
Watch for these warning signals in your kitchen:
- Full cooler: If you struggle to fit everything in
- Daily waste: Products in the trash every day
- Old labels: Products with dates from more than 3 days ago
- Creativity out of necessity: Your chef invents dishes to use up leftovers
The psychology behind overbuying
Why do we buy too much anyway? It boils down to a few thinking errors:
- Fear of shortages: "What if we run out?"
- Discount trap: "Buy 3, pay for 2" seems like a good deal
- Optimism: "We'll definitely sell more this week"
- No data: Guessing based on feeling instead of numbers
💡 Real-world example:
Restaurant De Eend always bought 10 kg of mussels per week "just to be safe". After collecting data for 3 months, they found:
- Average sales: 7.2 kg per week
- Peak week: 9.1 kg
- Optimal purchase: 8 kg (with 10% buffer)
Savings: €104 per month by buying 2 kg less.
This is a pattern we see repeatedly in restaurant financials - overbuying creates a cascade of hidden costs that eat into margins month after month.
How inventory control systems help
With tools like KitchenNmbrs, you see exactly:
- How much of each product you sell per week
- Which products turn over slowest
- Your average inventory value
- Automatic alerts for slow-moving items
This helps you buy based on data instead of gut feeling. Your inventory gets smaller, but you run less risk of shortages because you know exactly what you need.
How do you analyze your inventory turnover? (step by step)
Measure your current inventory
Count everything in your cooler and storage. Calculate what it's worth at purchase prices. This is your starting point.
Collect 4 weeks of purchase data
Write down exactly what you buy each week and how much it costs. Break it down by product category (meat, fish, vegetables).
Calculate your inventory turnover
Use the formula: monthly purchases divided by average inventory value. A score of 4-6 is normal for most products.
✨ Pro tip
Audit your 3 slowest-moving proteins every 2 weeks. These high-value items tie up the most cash and create the biggest losses if they sit too long.
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
What's a good inventory turnover rate for fresh products?
For fresh products like fish and meat, 6-8× per month is normal. This means your inventory refreshes every 4-5 days. Lower than 4× per month is too slow.
How do I avoid shortages if I buy less?
Use your sales data from the past few months. Buy your average sales plus a 10-15% buffer. For popular dishes, you can make the buffer a bit higher.
Is it better to buy large quantities for discounts?
Only if you're sure you'll use it before it expires. Weigh the discount against the risk of waste. Often you end up spending more.
Which products usually turn over slowest?
Specialty and seasonal products you buy "for variety". Also expensive ingredients for dishes that don't get ordered much. Check these first.
How often should I check my inventory turnover?
At least once a month for a full check. For problem products, you can check weekly. With a digital system, you see this automatically.
Should I calculate turnover by value or by weight?
By value gives you a better picture of cash flow impact. But tracking by weight helps with portion control and recipe consistency.
📚 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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