How much should you actually order to avoid both waste and stockouts? Most kitchens either order too much from fear of running out, or too little which forces expensive emergency orders. Here's the step-by-step method to calculate the right order quantity based on your real consumption data.
Why order quantities matter so much
Wrong order quantities hit your wallet twice: ordering too much creates spoilage waste, while ordering too little means costly emergency deliveries or lost sales when dishes aren't available.
💡 Example:
A restaurant orders 10 kg of salmon weekly but uses an average of 7 kg:
- Weekly waste: 3 kg × €22/kg = €66
- Annual waste: €66 × 52 weeks = €3,432
Correct ordering saves this restaurant €3,432 yearly on salmon alone.
The basic formula for optimal order quantity
The Economic Order Quantity (EOQ) formula calculates your ideal order quantity:
Optimal order quantity = (Average daily consumption × Delivery time in days) + Safety stock
- Average consumption: Daily usage under normal conditions
- Delivery time: Days between order and delivery
- Safety stock: Buffer for unexpected demand spikes
Calculating average consumption
Review consumption from the past 4-6 weeks for a reliable average. But skip extreme weeks like holidays or special events.
💡 Example salmon consumption:
- Week 1: 8 kg (6 days open = 1.33 kg/day)
- Week 2: 6 kg (6 days open = 1.00 kg/day)
- Week 3: 9 kg (6 days open = 1.50 kg/day)
- Week 4: 7 kg (6 days open = 1.17 kg/day)
Average consumption: (1.33 + 1.00 + 1.50 + 1.17) ÷ 4 = 1.25 kg/day
Determining safety stock
Your safety stock depends on consumption predictability and supplier reliability:
- Stable consumption + reliable supplier: 1-2 days extra
- Variable consumption: 2-3 days extra
- Perishable products: Maximum 2 days extra
- Non-perishable products: Up to 5 days extra
⚠️ Note:
Excessive safety stock increases waste. Too little creates stockout risk. Start conservatively and adjust through experience.
Accounting for seasons and trends
Order quantities should adapt to seasonal patterns. One of the most common blind spots in kitchen management is using static order quantities year-round instead of adjusting for predictable seasonal shifts.
- Summer: Higher salad demand, lower stew consumption
- Winter: More warm dishes, fewer cold appetizers
- Holidays: Different menu mix
- Vacation periods: Altered customer flow
Comparing different delivery frequencies
You can often choose delivery frequency. Calculate which option is more cost-effective:
💡 Delivery frequency comparison:
Consumption: 1.25 kg salmon/day
- Twice weekly delivery: (1.25 × 3.5) + 1 day buffer = 5.4 kg per order
- Weekly delivery: (1.25 × 7) + 2 days buffer = 11.3 kg per order
Twice weekly reduces inventory but may increase delivery costs.
Digital tracking vs. estimating
Many operators estimate consumption, but this often leads to incorrect orders. Digital tracking provides precise data:
- Manual: Daily usage logs
- Via POS system: Sales data per dish
- Via inventory software: Tools like KitchenNmbrs for automated calculations
Adjusting your order quantities
Review order quantities monthly and adjust for:
- Sustained sales changes
- Menu additions
- Menu removals
- Seasonal transitions
- Operating hour changes
How do you calculate optimal order quantities? (step by step)
Gather consumption data from 4-6 weeks
Note per product how much you used per week. Divide by the number of days you were open to get the daily average. Ignore extreme weeks like holidays.
Calculate your base order quantity
Multiply your average daily consumption by your supplier's delivery time. If your supplier takes 2 days and you use 1.5 kg per day, then your base is: 1.5 × 2 = 3 kg.
Add safety stock
Add 1-3 days extra as a buffer for unexpected busy periods. For perishable products maximum 2 days extra. Add this to your base order quantity for your final order.
✨ Pro tip
Track your 8 highest-cost ingredients over the next 30 days - these represent roughly 70% of your potential waste savings. Focus your calculation efforts here first for maximum impact.
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 if my supplier has inconsistent delivery times?
Add 1-2 extra days to your safety stock, or switch to a more reliable supplier. Unreliable deliveries cost more than the additional inventory expense.
How often should I recalculate order quantities?
Review monthly to ensure your averages remain accurate. Make immediate adjustments for major changes like menu updates, seasonal shifts, or significant sales pattern changes.
Should I split orders between multiple suppliers for the same product?
Calculate optimal quantities per supplier based on their delivery schedules and minimum orders. Choose suppliers offering the optimal price, quality, and reliability combination.
How do minimum order requirements affect my calculations?
Factor in supplier minimums when calculating. Determine if ordering slightly more for volume discounts is cheaper than switching to suppliers without minimums.
What's the risk of carrying too much safety stock?
Start with 1-2 days buffer and monitor waste levels. If you never stock out, reduce safety stock. If you frequently run short, increase it gradually.
How do I handle products with unpredictable shelf life?
For items like fresh herbs or seafood, reduce safety stock to maximum 1 day and consider more frequent deliveries. Track spoilage patterns to fine-tune quantities.
Should special events change my regular order calculations?
Calculate separate quantities for known events based on expected volume increases. Don't let special event weeks skew your regular consumption averages.
📚 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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