Most restaurants guess when to reorder ingredients, leading to waste or stockouts. Stock days reveal exactly how long your current inventory will last based on actual consumption patterns. You'll prevent over-ordering and never run out of critical ingredients again.
The formula for stock days
Calculating stock days is straightforward:
Stock days = Current inventory ÷ Average daily consumption
You'll need two numbers: your current stock quantity and your average daily usage of that product.
Step 1: Count your current inventory
Head to your storage areas and count exactly what's available. Focus on:
- Count only usable inventory (skip nearly expired items)
- Convert everything to the same unit (kilos, pieces, liters)
- Include all storage locations (walk-in, freezer, dry storage)
💡 Example:
You count your steak inventory:
- Walk-in cooler: 8 kg
- Freezer: 12 kg
- Total inventory: 20 kg
Step 2: Calculate your average daily consumption
Review your usage from the past 2-3 weeks. Divide this total by your actual working days.
💡 Example steak consumption:
- Week 1: 18 kg (6 working days)
- Week 2: 15 kg (6 working days)
- Week 3: 21 kg (6 working days)
- Total: 54 kg in 18 days
Average: 54 ÷ 18 = 3 kg per day
⚠️ Note:
Only count operating days, not closed days. Unless you're serving customers on those days too.
Step 3: Calculate your stock days
Now apply the formula:
💡 Example calculation:
- Current inventory: 20 kg steak
- Average consumption: 3 kg per day
- Stock days: 20 ÷ 3 = 6.7 days
So your steak will last almost 7 more operating days.
When should you reorder?
This depends on your supplier's lead time. If delivery takes 2 days, reorder when you've got 3-4 stock days remaining. You'll avoid running short.
- Next-day delivery: reorder at 2-3 stock days
- 2-day delivery: reorder at 3-4 stock days
- 3+ day delivery: reorder at 4-5 stock days
Stock days by product type
Different ingredients require different stock day targets:
- Fresh proteins: 3-5 days (limited shelf life)
- Produce: 4-7 days (varies by item)
- Frozen goods: 10-20 days (extended shelf life)
- Pantry staples: 14-30 days (very stable)
⚠️ Watch for seasons:
Summer brings higher salad usage, winter increases soup consumption. Adjust calculations for seasonal ingredients.
Digital tracking saves time
Manual counting and calculating consumes valuable time. After managing kitchen operations for nearly a decade, I've seen many operations switch to inventory management tools like KitchenNmbrs to automatically track stock levels. You input consumption data and instantly see remaining days for each ingredient.
How do you calculate stock days? (step by step)
Count your current inventory
Go to your fridge, freezer, and pantry. Count everything you have of that product. Convert to the same unit (kilos, pieces, liters).
Calculate average daily consumption
Look at consumption from 2-3 weeks back. Divide by number of working days. This gives you your average per day.
Apply the formula
Divide current inventory by daily consumption. The answer is your number of stock days. At 7 days you have a week's worth of inventory.
✨ Pro tip
Calculate stock days for your top 8 ingredients every Tuesday morning. This 15-minute routine prevents surprise shortages on your most critical menu items.
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
Should I count weekends in my calculation?
Only if you're operating on weekends. Always calculate using your actual service days, not calendar days.
What if my consumption varies significantly day to day?
Use a longer period (4-6 weeks) to calculate your average. This provides a more stable baseline for planning.
At how many stock days should I reorder?
This depends on supplier lead time. Generally: delivery time + 1-2 buffer days for unexpected delays.
Can I use this formula for beverages?
Absolutely. Count bottles, convert to liters, and calculate daily consumption the same way you would for food.
What if I have seasonal products?
Calculate separate averages for different seasons. Asparagus only moves in spring, while soup sales peak in winter.
How do I handle products with irregular usage spikes?
Track both your baseline consumption and event-driven spikes separately. Factor in scheduled catering or special events that dramatically increase usage.
📚 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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