Why the starting watts matter more than the running watts
A fridge spends most of its life drawing a few hundred watts. The hard moment is when the compressor kicks on: for about a second the motor pulls several times its running load[1] — manufacturer charts put a typical fridge’s startup at about four times its running watts. If your generator can’t deliver that burst, the fridge stalls or the generator trips its breaker — even though it could easily handle the running load.
That’s why every GennySize result shows two numbers. Look for both on a generator’s spec sheet: the rated (running) watts and the starting (peak, surge) watts.
Check your own fridge
Numbers vary by size and age. Find the label inside the door or on the back. If it lists only amps, multiply by the voltage[2]: a fridge rated at 6 A on 120 V draws about 720 W. Some charts list “additional starting watts” — add those to the running watts to get the total.
Refrigerator plus the rest of the house
Motors don’t all start in the same second, so you only add the single biggest startup jump on top of everything that’s running.
- Fridge + chest freezer: 1,200 W running, 3,400 W starting → at least 1,500 W rated (mid portable). Open in calculator
- Fridge + sump pump: 1,750 W running, 3,950 W starting → at least 2,188 W rated (mid portable). Open in calculator
- Fridge + furnace fan: 1,575 W running, 3,850 W starting → at least 1,969 W rated (mid portable). Open in calculator
We divide the running load by 0.8 because a generator shouldn’t sit above about 80% of its rating for hours.
Questions
Can a 2,000 W inverter generator run a refrigerator?
Usually yes for the running load. What decides it is the starting rating: check that the generator’s peak or surge watts cover your fridge’s startup.
Do I need a transfer switch just for the fridge?
Not if you plug the fridge straight into the generator with a heavy-duty outdoor extension cord. A transfer switch or interlock is for powering hardwired circuits like a furnace or well pump, and a qualified electrician installs it.[3]
How long does food stay safe without power?
About 4 hours in a closed fridge and about 48 hours in a full freezer.[4] A generator buys you time — keep the doors shut while you set it up.
Can the fridge take turns with other appliances?
It cycles on its own, so treat it as “must run together”. Things you control — microwave, hair dryer, washer — are the ones that can take turns.