Accurate power cost calculations can save you from losing 3-8% of your event revenue to unexpected electrical expenses. Most caterers underestimate generator rental, fuel consumption, and transport fees. Here's how to calculate every power-related cost and build them into your pricing structure.
What are the different power costs for outdoor catering?
Outdoor catering hits you with power expenses that don't exist in your regular kitchen. You're looking at four main cost categories:
- Generator rental: €50-150 per day, depending on capacity
- Fuel costs: €15-40 per day for diesel or petrol
- Generator transport: €25-75 for round trip
- Additional staff: Technician or extra time for setup
⚠️ Note:
Always calculate 20% extra capacity than you think you need. Equipment often requires more power during startup than normal operation.
Calculate your power consumption per device
You need exact wattage figures for proper cost calculations. Check the nameplate on each device - it'll show Watts or kW consumption.
- Warming plates: 300-500W each
- Electric chafing dishes: 400-600W each
- Coffee maker: 1000-1500W
- Electric coolers: 50-100W each
- Lighting: 200-500W total
💡 Example consumption calculation:
Event for 100 people, 6 hours:
- 4 warming plates: 4 × 400W = 1600W
- Coffee maker: 1200W
- 2 coolers: 2 × 75W = 150W
- Lighting: 300W
Total capacity: 3250W = 3.25 kW
Consumption 6 hours: 3.25 × 6 = 19.5 kWh
Choose the right generator and calculate rental costs
Your power consumption determines generator size. But don't just match the numbers - add 25% extra capacity for startup surges and unexpected equipment needs.
- Up to 5 kW: Small generator, €50-75 per day
- 5-10 kW: Medium generator, €75-120 per day
- 10-20 kW: Large generator, €120-200 per day
💡 Example generator selection:
With 3.25 kW consumption you need at least a 5 kW generator:
- Generator rental: €85 per day
- Transport: €50 round trip
- Fuel: €25 for 6 hours
Total power costs: €160
Calculate fuel consumption realistically
Generator fuel consumption varies with load percentage. Here's what diesel generators actually burn:
- At 50% load: 0.25 liters per kW per hour
- At 75% load: 0.35 liters per kW per hour
- At 100% load: 0.45 liters per kW per hour
Factor in current diesel prices around €1.60 per liter (this fluctuates regularly). From analyzing actual purchasing data across different restaurant types, fuel costs often surprise caterers who only estimate based on generator capacity alone.
💡 Example fuel calculation:
5 kW generator, 6 hours at 65% load:
- Consumption: 5 kW × 0.32 liters × 6 hours = 9.6 liters
- Cost: 9.6 × €1.60 = €15.36
Plus safety margin: €20 total for fuel
Pass power costs through to your catering price
Power expenses need to appear in your event pricing. You can split them per guest or list them as a separate line item.
⚠️ Note:
Never absorb power costs into your margins, even with fixed-price packages. These expenses can represent 3-8% of total event revenue and will destroy your profitability.
💡 Example pass-through:
Event 100 people, total power costs €160:
- Per person: €160 ÷ 100 = €1.60
- Or as fixed item: "Power supply €160"
At €25 per person catering price this represents 6.4% of your revenue
Alternatives to generators
Sometimes you can avoid generator costs entirely:
- Location with power connection: Ask about 16A or 32A availability
- Battery-powered equipment: Battery warming plates, 12V coolers
- Gas equipment: Gas chafing dishes instead of electric versions
- Hybrid solution: Small generator combined with gas heating
A food cost calculator like KitchenNmbrs tracks all event expenses including power supply costs per event, so you'll know exactly what each catering type actually costs you.
How do you calculate power costs for outdoor catering? (step by step)
Inventory all your electrical equipment
Make a list of all equipment you need and note the capacity in Watts. Add everything up and convert to kW (divide by 1000). Don't forget lighting and cooling.
Calculate your total energy consumption
Multiply your total capacity in kW by the number of hours the event lasts. This gives you the consumption in kWh. Calculate 25% extra for startup peaks.
Choose generator and calculate all costs
Select a generator with sufficient capacity. Add up: daily rental costs, transport costs, fuel costs and any additional staff costs for operation.
✨ Pro tip
Document your generator's actual fuel consumption over 3-4 events by checking the tank before and after. This gives you precise consumption rates instead of guessing, and you can adjust your fuel cost estimates within €5-10 accuracy.
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 kW generator do I need for 50 people catering?
For 50 people you'll typically need 2-4 kW, depending on your equipment mix. Add 25% safety margin, so plan for at least a 3-5 kW generator. Total costs run approximately €60-90 per day including fuel.
Can I charge power costs separately to customers?
Absolutely - many caterers list power supply as a separate line item, especially for large events. Transparent pricing often works better than hiding costs in per-person rates. Customers understand outdoor events need generators.
What if the location has power but insufficient capacity?
Always verify available connections beforehand. A standard household outlet (16A) maxes out at 3.6 kW. You'll need 32A three-phase power for higher capacity, or you're back to generators anyway.
📚 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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