What size generator does a food truck need?
Short answer
Most food trucks and trailers need a 7 to 12 kW generator. Add up the running watts of every electric appliance plus lights, A/C and the hood fan, add the extra current the biggest compressor draws when it starts, and size the generator so it runs at no more than 80% of its rating. A taco trailer with A/C runs about 5,160 W and needs a 7 kW generator; coffee and soft-serve trailers need more because espresso machines and freezers are electric.
Last reviewed by the Trailer3D editorial team. Uses the same equipment data and checks as our 3D studio.
Sized so the generator runs at no more than 80% of its rating and can start the largest motor while everything else is on. Gas appliances are not counted; their igniters and fans draw very little.
How the calculator works
Running load: every appliance's current at 120 V, plus air conditioning at about 8 A per 12,000 BTU, interior lights (3 A) and a hood exhaust fan (6 A) when there is grease equipment.
Starting load: compressors and motors (fridges, freezers, ice makers, soft serve, blenders, A/C) draw about 3× their running current for a second when they start. We add that extra for the single biggest motor, because they rarely all start at once.
Generator size: the larger of the running load × 1.25 (so the generator stays under 80% for long service) and the starting peak ÷ 1.2 (most generators can start loads about 20% above their running rating), rounded up to a common generator size.
30 amp or 50 amp?
A 30 A, 120 V hookup gives you about 3,600 W, enough for a coffee cart with one small machine or a cold menu with a couple of fridges. A 50 A, 120/240 V hookup gives up to 12,000 W and suits almost every hot kitchen. If the calculator shows more than about 24 A, plan on 50 A; above 40 A, talk to your builder about a 100 A panel.
What it leaves out
Gas appliances: their igniters and blowers draw very little. Espresso machines and soft-serve machines are often 208 to 240 V; the calculator converts them to their 120 V equivalent wattage, which is what the generator has to supply. Always check the nameplate of the exact model you buy.
Worked examples
| Menu | Running load | Generator | Shore power |
|---|---|---|---|
| Tacos | 5,160 W | 7 kW | 100 A |
| BBQ | 5,760 W | 9 kW | 100 A |
| Pizza | 3,840 W | 5.5 kW | 50 A |
| Burgers | 5,160 W | 7 kW | 100 A |
| Gyro | 5,280 W | 7 kW | 100 A |
| Wok | 6,960 W | 9 kW | 100 A |
| Ice cream | 7,800 W | 15 kW | 100 A |
| Smoothies | 6,360 W | 9 kW | 100 A |
| Coffee | 9,360 W | 12 kW | 100 A |
| Breakfast | 8,280 W | 12 kW | 100 A |
Menus use the equipment our studio places for that menu (see menu benchmarks). Estimates for planning, not engineering approval: your builder, health department and fire marshal have the final word.
Questions
Can I run a food truck on a 3,500 W generator?
Only a very light menu: a coffee cart with a small machine, or pre-packaged cold food with one fridge. As soon as you add A/C or an espresso machine, 3,500 W is not enough.
Inverter or conventional generator?
Inverter generators are much quieter, which many events and cities require, and their clean power suits POS systems and espresso controls. Above about 9 kW, built-in conventional generators are more common.
Do I need a generator if I always park at events with power?
Not for power, but many events only offer 30 A or 20 A circuits. Use the shore-power line in the calculator to check what you will need to ask the organiser for.
Sources and assumptions
- Equipment current draw: Trailer3D studio catalogue, from manufacturer spec sheets
- Generator loading: NEC Article 445 and manufacturer guidance to run at 80% or less for continuous loads
- Motor starting current: typical 2 to 3× locked-rotor multiple for small hermetic compressors