Generator sizing Updated June 2026
What Size Generator to Run a Refrigerator?
By Yann Buf, HVAC tech 5 min read Standards-reviewed
A standard refrigerator/freezer needs 150-200W running and 600-800W starting. A larger side-by-side with ice maker needs up to 1,200W starting. A tiny 3,500W generator can easily run your fridge plus a dozen other essentials.
Refrigerator Power: Less Than You Think
Most people are surprised to learn that a refrigerator uses very little power while running — typically 150-200W for a modern Energy Star model. The issue is the starting surge, which can be 3-5x the running wattage as the compressor kicks on.
Even with this surge, a refrigerator is one of the easiest appliances to power with a generator. A 1,500W generator can run a refrigerator AND lights AND a furnace fan. In fact, the fridge is rarely the limiting factor — it's usually the AC, sump pump, or well pump that determines generator size.
When sizing a generator that includes a refrigerator, add 800-1,200W to account for the starting surge, but don't worry about the running load (150-200W is negligible).
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Power Your Fridge During an Outage
- Standard refrigerator (18-22 cu ft): 150W running, 600W starting — any generator over 1,000W works
- Side-by-side with ice maker (22-26 cu ft): 200W running, 800W starting
- Large French door (26-30 cu ft): 250W running, 1,200W starting
- Chest freezer: 100W running, 500W starting — very easy to power
- Multiple refrigerators/freezers: Add running watts, use the highest single starting surge
Frequently asked questions
How long can I run a refrigerator on a generator?
Indefinitely — refrigerators cycle on and off via thermostat, so the generator only powers the compressor when it's actively cooling. On a 3,500W generator with a full tank of gas, you can run a refrigerator continuously for 8-12 hours per tank refill.
Will power surges from a generator damage my refrigerator?
Most modern refrigerators have built-in surge protection. However, to be safe, use an inverter generator (clean sine wave output) rather than a conventional generator (modified sine wave). The Honda EU series and similar inverter generators provide the cleanest power.
Should I unplug my refrigerator before connecting a generator?
Yes — always turn off and unplug major appliances before connecting generator power, then reconnect one at a time. This prevents the starting surge of multiple devices from hitting the generator simultaneously.