A restaurant owner recently discovered their butter supplier quietly reduced packages from 500g to 450g while keeping the €3.20 price. This sneaky practice instantly increased their per-kilogram costs by 11%. Here's how to calculate and respond to these hidden cost increases.
Why suppliers switch to smaller packages
Suppliers shrink portions to cut costs without raising prices. A 500-gram pack of butter becomes 450 grams, but the price stays €3.20. You often only notice after your chef complains that ingredients run out faster.
💡 Example:
Your supplier now delivers salmon in 180-gram portions instead of 200 grams:
- Old price: €4.50 for 200g = €22.50/kg
- New price: €4.50 for 180g = €25.00/kg
- Cost increase: €2.50 per kg = 11% more expensive
With 50 salmon dishes per week: €250 extra costs per year
Calculate the hidden cost impact
The real impact lies in the difference between old and new per-kilogram price. Many business owners only see that the package price stays the same, but miss that they're getting less product.
Formula for cost increase per kg:
New price per kg = Package price / (New weight in grams / 1000)
Cost increase % = ((New price per kg - Old price per kg) / Old price per kg) × 100
💡 Example calculation:
Chicken fillet package at €8.50:
- Previously: 1 kg = €8.50/kg
- Now: 850 grams = €8.50 / 0.85 = €10.00/kg
- Cost increase: €1.50/kg = 17.6% more expensive
Impact on your food cost percentage
A higher purchase price automatically means higher food cost. If your menu price stays the same, your margin drops immediately. From analyzing actual purchasing data across different restaurant types, portion reductions of 10-15% are becoming increasingly common.
⚠️ Note:
A 10% cost increase on an ingredient doesn't mean your food cost rises by 10%. It depends on how much this ingredient makes up of your total dish.
Formula for food cost impact:
New food cost = ((Old ingredient costs - Old ingredient) + New ingredient) / Sales price excl. VAT × 100
💡 Example food cost impact:
Steak at €32.00 (excl. VAT €29.36):
- Old ingredient costs: €9.50 (food cost 32.4%)
- Beef was €3.20, becomes €3.70 (+€0.50)
- New ingredient costs: €10.00
- New food cost: 34.1% (+1.7 percentage points)
With 100 steaks per month: €50 less profit
Options to limit the impact
You have four options once suppliers start delivering smaller portions:
- Raise menu price: Compensate for the cost increase by adjusting your sales price
- Find another supplier: Check if competitors still have normal portion sizes
- Adjust portion size: Serve slightly less to stay within your food cost
- Adjust recipe: Partially replace expensive ingredient with cheaper alternative
When raising menu price makes sense
If the cost increase is more than 5% of your ingredient costs, a price increase is often unavoidable. Calculate how much you need to raise prices at minimum to maintain your margin.
Formula for minimum price increase:
New minimum sales price = New ingredient costs / (Desired food cost % / 100) × 1.09 (VAT)
💡 Example price increase:
Pasta with ingredient costs from €5.50 to €6.20:
- Desired food cost: 30%
- Minimum price excl. VAT: €6.20 / 0.30 = €20.67
- Minimum price incl. VAT: €20.67 × 1.09 = €22.53
- Old price was €21.50, new price €22.50
Price increase: €1.00 per portion
Monitoring and early warning
The smartest defense is early detection. Check your delivery invoices monthly for changes in package sizes. Pay special attention to products that make up a large portion of your purchases.
- Compare weights on packing slips with previous month
- Check if you need to order more frequently for the same volume
- Monitor your food cost per dish - increases can point to smaller portions
- Ask your chef if ingredients run out faster than usual
How do you calculate the margin impact? (step by step)
Determine the new price per kilogram
Divide the price per package by the new weight in kilograms. A €5.00 pack with 800 grams becomes €5.00 / 0.8 = €6.25 per kg. Compare this with the old price per kilogram.
Calculate the cost increase percentage
Subtract the old price per kg from the new one, divide by the old price and multiply by 100. This gives you the exact percentage by which this ingredient becomes more expensive.
Calculate the impact on your food cost
Replace the old ingredient price in your recipe calculation with the new one. Divide the new total by your sales price excl. VAT and multiply by 100 to get your new food cost percentage.
✨ Pro tip
Calculate the exact margin impact within 48 hours of receiving your first smaller package. Compare your per-kilogram costs from the last 3 months to spot patterns - suppliers often reduce portions gradually rather than all at once.
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
Can I prevent these kinds of changes through contracts?
Rarely with large suppliers. However, you can make agreements about timely communication of changes, so you're not caught off guard.
Which products have the highest risk of portion shrinking?
Meat, fish, and dairy have the biggest impact because they often make up 30-60% of your ingredient costs. Keep these categories under extra watch.
Do I need to adjust my menu price immediately when portions get smaller?
Only if the impact is more than 1 percentage point on your food cost. For smaller changes, you can first look at other savings or alternative suppliers.
📚 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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