Self-grown ingredients seem free, but they definitely cost money. You invest in containers, potting soil, seeds, water, and time. To calculate your margin correctly, you need to factor these costs into your cost per portion.
Why self-grown ingredients aren't free
Many restaurant owners think their own herbs or vegetables don't cost money. That's not true. You've made investments and you spend time on maintenance.
⚠️ Watch out:
If you don't factor in self-grown ingredients, your margin will look higher than it actually is. This gives you a distorted picture of your profitability.
Calculate your costs per kilo or per plant
For an accurate cost price, you need to gather all expenses and divide them by your harvest.
💡 Example: Growing basil
Annual costs for 20 basil plants:
- Containers (20x €3): €60
- Potting soil per year: €25
- Seeds/seedlings: €15
- Water (estimated): €20
- Time (2 hours/week × 52 × €15/hour): €1,560
Total per year: €1,680
Harvest: 10 kg basil per year
Cost price: €1,680 / 10 kg = €168/kg
Time is your biggest cost item
Most entrepreneurs forget to factor in their own time. If you spend 2 hours per week on your containers, calculate your hourly rate accordingly.
- Conservative: €15/hour (minimum wage)
- Realistic: €25/hour (what you earn as an entrepreneur)
- Full: €40/hour (opportunity costs)
💡 Example: Growing tomatoes
Setup for 15 tomato pots on terrace:
- Containers: €90 (depreciation 3 years = €30/year)
- Soil, fertilizer, seedlings: €45/year
- Water: €30/year
- Time: 3 hours/week × 6 months × €20/hour = €360/year
Total costs: €465/year
Harvest: 25 kg tomatoes
Cost price: €465 / 25 kg = €18.60/kg
Compare with supplier purchase price
Now you can honestly compare whether growing your own makes sense. Look at the price you pay your vegetable supplier for the same quality.
⚠️ Watch out:
Compare apples with apples. Organic basil from your supplier might cost €40/kg, but standard basil €15/kg. What quality are you growing?
Apply the cost price to your recipes
Use your calculated cost price per kilo in your recipe cards, just like with purchased ingredients.
💡 Example: Margherita pizza
Ingredients per pizza:
- Dough: €0.65
- Tomato sauce (own tomatoes, 50g): €0.93
- Mozzarella: €1.20
- Basil (own, 5g): €0.84
- Olive oil: €0.15
Cost price per pizza: €3.77
Selling price €14.50 incl. VAT = €13.30 excl. VAT
Food cost: 28.4%
Factor in seasons and risks
Growing your own comes with risks that your supplier doesn't have:
- Failed harvest: Due to disease or weather
- Seasonal: No fresh basil in winter
- Quality variations: Not every harvest is equally good
Add a risk markup of 10-20% to your cost price to compensate for this.
How do you calculate the cost price of self-grown ingredients?
Gather all annual costs
Make a list of containers, potting soil, seeds, water, and maintenance. Depreciate containers over 3-5 years. Don't forget your own time (minimum €15/hour).
Estimate your annual harvest
Keep track of how many kilos you harvest per year from each plant. Include failed harvests in your average. Be realistic about seasons.
Calculate cost price per kilo
Divide your total annual costs by your total harvest in kilos. Add a 10-20% risk markup for failed harvests. This is your cost price for recipes.
✨ Pro tip
Keep a log of your harvests and costs. After a year you'll see exactly what growing your own costs and you can make an honest comparison with your supplier.
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
Do I really need to count my own time?
Yes, absolutely. Your time has value and you could spend it on other tasks. Calculate at least €15/hour, but €25/hour is more realistic for an entrepreneur.
What if my self-grown ingredients end up costing more than buying them?
Then you know that growing your own doesn't offer a financial advantage. You can still do it for quality or marketing, but factor the real costs into your prices.
How do I handle seasons if I can't harvest year-round?
Calculate your annual costs throughout the whole year, even if you only harvest for 6 months. Your containers and time cost money all year, so your cost price per kilo will be higher.
Can I use this cost price for marketing?
You can say you use your own ingredients, but don't claim they're 'free'. Focus on quality and freshness, not costs.
What if a harvest fails?
That's why you add a risk markup of 10-20% to your cost price. Failed harvests are part of growing your own and need to be compensated by successful ones.
📚 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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