The purchase price per portion differs enormously between whole lettuce heads and pre-packaged lettuce. Many kitchens calculate incorrectly by not accounting for trimming loss and labor costs. This article shows you step by step how to calculate the real costs of both options.
The difference between heads and pre-cut
With lettuce purchasing you have two main options: whole heads or pre-packaged lettuce. Both have different cost structures that you need to calculate through.
💡 Example comparison:
For 100 portions of salad you need 5 kg of clean lettuce:
- Whole heads: €1.20/head, 8 heads needed = €9.60
- Pre-packaged lettuce: €3.20/kg, 5 kg needed = €16.00
But this isn't the whole story...
Calculate trimming loss for whole heads
Whole lettuce heads always have trimming loss. You throw away the outer leaves, cut off the stem and lose volume from washing and spinning.
💡 Trimming loss calculation:
Iceberg lettuce head of 800 grams:
- Outer leaves: 150 grams waste
- Stem: 80 grams waste
- Washing and draining loss: 70 grams waste
Usable: 500 grams (62.5% yield)
The formula for actual price per kilo after trimming loss:
Actual price = Purchase price per head / (Usable weight in kg)
💡 Actual cost price:
Head at €1.20 with 500 grams usable:
€1.20 / 0.5 kg = €2.40 per kg clean lettuce
⚠️ Attention:
Many kitchens calculate with the purchase price per head but forget the trimming loss. Then whole lettuce seems much cheaper than it really is.
Include labor time in the calculation
Whole heads require more labor than pre-packaged lettuce. Add this time as a cost item.
- Cleaning and cutting: 3-5 minutes per head
- Washing and spinning: 2-3 minutes per head
- Cleanup and waste disposal: 1-2 minutes per head
💡 Labor cost calculation:
8 heads for 100 portions, 6 minutes per head:
- Total time: 48 minutes = 0.8 hours
- Kitchen hourly rate: €18 (incl. employer taxes)
- Labor costs: 0.8 × €18 = €14.40
Per 100 portions: €0.14 labor cost per portion
Total comparison per portion
Now you can compare the real costs per portion. Add up all cost items for a fair comparison.
💡 Total overview 100 portions:
Whole heads:
- 8 heads at €1.20 = €9.60
- Labor costs = €14.40
- Total = €24.00
Pre-packaged lettuce:
- 5 kg at €3.20 = €16.00
- Labor costs = €0 (ready to use)
- Total = €16.00
Per portion: €0.24 vs €0.16 - pre-packaged is €0.08 cheaper
When whole heads are still more economical
Whole heads can be more economical with:
- Large volumes: At 500+ portions per day the labor time per portion becomes lower
- Low labor costs: If you cut it yourself or staff costs less than €15/hour
- Less trimming loss: With fresh, small heads the yield can increase to 75%
- Quality difference: If guests notice the difference and pay more for fresh lettuce
⚠️ Attention:
Always calculate with your own figures. Trimming loss and labor costs differ per kitchen. Measure for a week to know your actual yield.
Include seasonal differences
Lettuce prices fluctuate significantly by season. Whole heads can cost €0.80 in summer and €2.00 in winter. Pre-packaged lettuce has fewer price fluctuations.
Therefore recalculate each month which option is more economical. A system like KitchenNmbrs helps track these calculations and automatically adjust your cost price when suppliers change their prices.
How do you calculate the actual purchase price per portion?
Measure the trimming loss of whole heads
Weigh 10 heads before and after cleaning. Calculate the average yield percentage. This becomes your standard for all calculations.
Calculate the actual price per kilo
Divide the price per head by the usable weight in kilograms. For pre-packaged lettuce use the supplier's price per kilo directly.
Add labor costs
Measure how much time you spend cleaning per head. Multiply by your hourly rate (including employer taxes) and add to the ingredient costs.
Compare total costs per portion
Divide the total costs by the number of portions you make with it. Choose the option that is cheapest per portion for your situation.
✨ Pro tip
Buy only whole heads for a week and weigh everything. The next week only pre-packaged. That way you know exactly what your real costs are instead of guessing.
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
How much trimming loss should I account for with iceberg lettuce?
Average 35-40% trimming loss with iceberg lettuce. This means 60-65% yield. Measure this yourself for a week to know your own percentage.
Should I include labor costs in cost price calculation?
Yes, labor costs are real costs. If you spend 10 minutes cutting lettuce at €18/hour, that costs €3.00 in labor that you need to pass through.
When is pre-packaged lettuce always more expensive?
With very small quantities (under 20 portions per day) and if your labor costs are very low. But always calculate it through with your own figures.
How often should I redo this calculation?
At least monthly, because lettuce prices fluctuate significantly by season. In winter whole heads can become 2-3x more expensive than in summer.
Can I use this for other vegetables too?
Yes, the same method applies to all vegetables with trimming loss: peppers, onions, carrots, etc. Always measure your own yield percentage.
📚 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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