Most restaurant owners can't explain why their food costs spike unexpectedly from week to week. They track purchases religiously but ignore inventory changes entirely. You're missing half the equation without accounting for what actually leaves your kitchen.
Why calculate weekly food cost?
Weekly food cost reveals your true ingredient consumption. It's not the same as what you purchased because inventory levels shift constantly. Purchases alone tell you what arrived, not what customers actually ate.
💡 Example:
Week 1: You buy €2.000 worth, but your inventory increases by €300. Your actual consumption is €1.700.
Week 2: You buy €1.500 worth, but your inventory decreases by €200. Your actual consumption is €1.700.
Purchases differ, but consumption is the same!
The formula for weekly food cost
Here's the calculation:
Weekly Food Cost = Beginning Inventory + Purchases - Ending Inventory
This shows actual consumption in euros. For your percentage, divide by revenue excluding VAT.
⚠️ Note:
Always calculate with your revenue excl. VAT. The price on your menu is incl. 9% VAT. Divide by 1.09 for the correct revenue.
Count inventory correctly
Consistency matters more than perfection. Count at identical times each week - Monday morning before opening works well. Include everything you've got:
- Refrigerator and freezer
- Dry goods
- Beverages (if you calculate food cost incl. beverages)
- Opened products (estimate the residual value)
💡 Example calculation:
Monday March 1st: inventory €3.200
- Week 1 purchases: €2.400
- Monday March 8th: inventory €2.800
- Week 1 revenue: €8.500 incl. VAT = €7.798 excl. VAT
Food cost: €3.200 + €2.400 - €2.800 = €2.800
Food cost %: €2.800 / €7.798 × 100 = 35.9%
What do the numbers mean?
Most restaurants run between 28% and 35% weekly food cost. Above 35% consistently? You're bleeding money.
- Below 25%: Possibly too small portions or too high prices
- 25-35%: Healthy margin for most restaurants
- 35-40%: On the high side, check your portions and purchases
- Above 40%: Loss-making, immediate action needed
One of the most common blind spots in kitchen management is assuming that consistent purchasing equals consistent food costs. But inventory fluctuations can swing your actual costs by 5-8 percentage points week to week.
Common mistakes
Inconsistent counting kills accuracy faster than anything else. Count more items one week, fewer the next, and your numbers become meaningless. Other pitfalls:
- Staff forgets to record purchases
- Small purchases (spices, oil) not included
- Calculating with revenue incl. VAT
- Not deducting waste from inventory
⚠️ Note:
If your inventory increases every week, you're buying too much. If it decreases every week, you don't have enough buffer and risk empty shelves.
Digital vs manual tracking
Excel sheets and paper lists still dominate most kitchens. They work but eat time and breed errors. Tools like KitchenNmbrs calculate everything automatically once you input inventory and purchases.
Digital tracking shows trends instantly and eliminates manual math. But remember - apps only calculate what you feed them. Accurate counting remains your job.
How do you calculate weekly food cost? (step by step)
Count your beginning inventory
Count Monday morning (or fixed time) all inventory. Note the value of everything in refrigerator, freezer and dry goods. Estimate opened products at residual value.
Record all purchases for the week
Keep track of what you've purchased this week. Add up all receipts: meat, fish, vegetables, spices, oil. Don't forget small purchases.
Count your ending inventory
Count all inventory again next Monday the same way. Make sure you count consistently: same time, same method.
Calculate your consumption
Use the formula: Beginning Inventory + Purchases - Ending Inventory = Actual consumption. This is your food cost in euros for this week.
Calculate your food cost percentage
Divide your consumption by your revenue excl. VAT and multiply by 100. At 9% VAT: revenue incl. VAT divided by 1.09.
✨ Pro tip
Track your food cost daily for 2 weeks straight, then compare to your weekly calculation. This reveals exactly where the biggest consumption spikes happen and helps you spot theft or waste patterns.
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 include beverages in my food cost calculation?
That depends on what you want to measure. For pure food cost, only include food. For total cost of goods sold (COGS), also include beverages.
How often should I count my inventory?
For weekly food cost at least once a week at the same time. Many restaurants do this Monday morning before opening, when inventory is at its lowest.
What if my food cost is different every week?
That's normal. Look at the average over 4 weeks. Large fluctuations can indicate inconsistent counting or varying purchases.
How accurate does my inventory count need to be?
Be as accurate as possible, but perfection isn't necessary. An error of €50 on €3000 inventory has little impact on your food cost percentage.
What if my inventory increases every week?
Then you're probably buying too much. Your food cost will appear lower, but you have more money tied up in inventory. Check if everything is used in time.
Should I count prep items at cost or menu price?
Always use ingredient cost, never menu price. If you've prepped €50 worth of vegetables into soup, count it as €50 inventory, not the soup's selling price.
📚 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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