Nearly 73% of restaurants underestimate their true food costs by ignoring hidden expenses in self-grown ingredients. Even though you don't write checks to suppliers, you're still investing real money in seeds, labor, and space. Skip these calculations and your profit margins become dangerously misleading.
Why self-grown ingredients cost money
Growing herbs, lettuce, or microgreens in-house feels free. But there's no such thing as a free lunch—or free basil.
- Seeds, potting soil and pots cost money
- Electricity for grow lights or heating
- Water and nutrients for the plants
- Your time or your staff's time
- Space that could generate revenue elsewhere
⚠️ Note:
Ignore these costs and you'll price dishes too low. Your "profitable" pasta might actually be bleeding money.
The cost price formula for self-grown ingredients
Calculate your true cost per kilogram by dividing total expenses by harvest weight:
Cost price per kg = (Material costs + Labor costs + Overhead costs) / Total harvest in kg
? Example: Growing basil
Twenty pots of basil over 6 weeks yield 2 kg.
- Seeds and potting soil: €15
- Electricity for grow light: €25
- Water and nutrients: €8
- Labor costs (2 hours weekly at €15): €180
Total: €228 for 2 kg = €114 per kg
Calculate material costs
Track every physical input for one growing cycle:
- Seeds: Purchase price divided by cycles per packet
- Potting soil: Fresh each cycle or reusable?
- Pots: Initial cost spread across their lifespan
- Nutrients: Fertilizers, compost, specialized feeds
Include labor costs
Time costs money whether it's yours or your team's. After managing kitchen operations for nearly a decade, I've learned that unpaid labor still shows up in your bottom line—just in different ways.
- Sowing, potting, daily watering
- Harvesting and prepping for kitchen use
- Cleaning equipment between cycles
? Example: Labor costs for microgreens
Microgreens need 30 minutes weekly for 3 weeks = 1.5 total hours.
- Staff rate: €15 per hour
- Labor per cycle: 1.5 × €15 = €22.50
- Harvest: 500 grams
Labor cost: €45 per kg
Pass on overhead costs
Don't forget the invisible expenses:
- Electricity: Grow lights and heating mats
- Water: Extra consumption from frequent misting
- Space: Rent allocation for growing area
- Failures: Cycles that don't produce
⚠️ Note:
Build in a 10% failure rate. If one in ten cycles fails completely, spread those costs across your successful harvests.
From cost price to portion price
Convert your per-kilogram cost into recipe portions:
Cost per portion = (Cost price per kg / 1000) × Grams per portion
? Example: Basil in pasta
Your basil costs €114 per kg. Each pasta gets 5 grams.
- Per gram: €114 ÷ 1000 = €0.114
- Per portion: 5 × €0.114 = €0.57
Compare that to wholesale basil at €40-60 per kg.
Does growing your own make sense?
Compare your calculated cost against market prices:
- Clear win: Lower cost plus guaranteed availability
- Worth it anyway: Higher cost but superior quality or marketing value
- Break even: Similar cost but eliminates supply chain risks
Systems like KitchenNmbrs let you track both purchased and homegrown ingredients at their true costs. Your food cost calculations stay accurate regardless of ingredient source.
How do you calculate the cost price of self-grown ingredients?
Gather all material costs per cycle
Note what you spend on seeds, potting soil, pots and nutrients for one complete growing round. Divide durable materials (pots, trays) by the number of cycles you can use them for.
Calculate labor costs realistically
Keep track of how much time you spend per week on sowing, caring and harvesting. Multiply by a realistic hourly rate (€15-20 per hour) and add up for the entire cycle.
Add overhead costs and losses
Include electricity, extra water and space costs. Don't forget the failure rate: if 10% fails, divide your costs by 90% of your expected harvest.
Divide total costs by actual harvest
Cost price per kg = (Material + Labor + Overhead) / Total harvest in kg. Measure your harvest in grams for the most accurate calculation.
Compare with purchase price of comparable quality
Check if your self-grown ingredient is cheaper than buying from the wholesaler. Don't forget to factor in quality and availability in your decision.
✨ Pro tip
Track your actual harvest weight in grams after every 6-week cycle. Average your yields over 4 cycles to eliminate seasonal variations and get reliable cost-per-kilogram numbers for recipe costing.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
Calculate it yourself?
Our free food cost calculator does it in seconds.
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Frequently asked questions
Should I count my own time as labor costs?
How do I calculate electricity costs for grow lights?
What if growing costs more than buying?
Should I include failed harvests in the calculation?
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
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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