Every fall, my phone starts ringing with the same worried question. A storm is coming, the forecast looks ugly, and someone wants to know if the little generator in their garage can keep the fridge from turning into a science experiment.
The good news is that a refrigerator is one of the easier things to back up. It doesn’t sip power all day long, and even a modest generator can handle it with room to spare. The tricky part isn’t the running load. It’s that split-second gulp of power when the compressor kicks on.
So let’s talk about what size generator to run a refrigerator, using real numbers I’ve measured on actual jobs, not the optimistic figures printed on a box.
Key takeaways
- A typical fridge draws 100–200 running watts but spikes to 800–1,200 watts for a second or two when the compressor starts.
- A 2,000-watt inverter generator runs a refrigerator comfortably and leaves headroom for lights and a phone charger.
- Match the generator’s starting watts to the fridge’s surge, not just the running watts on the nameplate.
- Run the generator outdoors only, at least 20 feet from any window or door, every single time.
What size generator to run a refrigerator, in plain numbers
Here’s the short answer for the impatient: a 2,000-watt generator will run almost any household refrigerator, and a 1,000-watt unit will run most modern energy-efficient ones. I keep a 2,200-watt inverter on my own truck and it’s never blinked at a fridge.
The reason people get nervous is the gap between two very different numbers. A fridge might only run at 150 watts, but the moment that compressor motor spins up, it briefly pulls five to eight times that. If your generator can’t cover the spike, it stalls or trips, and you’re back to warm milk.
Look for a sticker inside the fridge door or on the back that lists amps. Multiply amps by 120 volts to get running watts. A fridge rated at 1.5 amps is only about 180 running watts, which surprises a lot of folks.
Running watts vs. starting watts (the part that trips people up)
Motors are greedy at startup. A refrigerator compressor is a small induction motor, and it needs a jolt of extra current to get moving from a dead stop. Electricians call this locked-rotor amperage, but you can just think of it as the surge.
On a job last winter, I clamped a meter on a customer’s 21-cubic-foot side-by-side. Running, it pulled 132 watts. At startup, it jumped to just over 1,100 watts for about a second and a half, then settled right back down.
Why this matters for your generator
Generators list two ratings: running (or rated) watts, and starting (or peak) watts. A 2,000-watt inverter usually means about 1,600 running watts and 2,000 starting watts. That starting number is what has to cover your compressor surge.
A mistake I see all the time is someone buying a 1,000-watt generator because the fridge “only uses 150 watts.” Then it stalls every time the compressor cycles, and they assume the generator is defective. It isn’t. It just couldn’t swallow the surge.
A quick wattage table for common refrigerators
These are measured ballpark figures. Your unit may vary, but they’re close enough to plan around.
| Refrigerator type | Running watts | Startup surge |
|---|---|---|
| Compact / mini fridge | 60–90 W | 300–500 W |
| Modern Energy Star top-freezer | 100–150 W | 700–1,000 W |
| Large side-by-side | 150–220 W | 1,000–1,300 W |
| Older fridge (pre-2005) | 250–400 W | 1,300–1,800 W |
| Chest freezer (separate) | 100–200 W | 800–1,200 W |
Notice that older units are the real power hogs. If you’re backing up a 20-year-old garage fridge, don’t cut it close on generator size. That surge can be brutal.
What size fits your situation
Most people aren’t running only a refrigerator. You want a few lights, a phone charger, maybe the internet router. So think about the total, not just the fridge.
- Just the fridge, nothing else: a 1,000-watt inverter works for most modern units.
- Fridge plus lights, phones, and Wi-Fi: step up to 2,000 watts for breathing room.
- Fridge plus a separate chest freezer: 2,000–2,500 watts so both compressors can surge without fighting.
- Fridge plus a sump pump or well pump: you’re now in 3,500-plus territory, since those motors surge hard too.
That last point trips people up during floods. If you also need to keep a basement dry, read up on sizing a generator for a sump pump before you buy, because that pump’s surge can dwarf the fridge. Same goes if you’re on a private water system and want to plan around sizing a generator for a well pump.
For a full picture of adding up every circuit you care about, our walkthrough on how to size a generator for your home lays out the math step by step.
Fuel, runtime, and what it actually costs to keep food cold
A refrigerator doesn’t run constantly. The compressor cycles on and off, so over a day it’s only actually running maybe 8 to 12 hours total. That’s great news for your fuel bill.
A 2,000-watt inverter generator running just a fridge will sip fuel. In eco mode, I’ve seen one go 10 to 12 hours on a single gallon of gas, because the engine throttles down when the compressor is resting.
At roughly $3.50 a gallon, keeping your fridge alive costs somewhere around $7 to $10 a day. Compare that to tossing a fridge full of groceries, which runs $200 to $400, and the generator pays for the food many times over.
Never run a portable generator in a garage, shed, or near an open window, even for “just a few minutes.” Carbon monoxide is invisible and kills fast. Keep the generator at least 20 feet from the house with the exhaust pointed away. The CPSC generator safety guidance is worth reading before your first outage.
Getting the power from generator to fridge safely
The simplest, safest method is a heavy-duty extension cord rated for the load, run straight from the generator to the fridge. Use a 12-gauge outdoor cord and keep it as short as practical. Thin, cheap cords cause voltage drop that makes the compressor work harder.
Never plug a generator into a wall outlet to “backfeed” the house. That’s illegal in most places and genuinely dangerous, since it can send power back down the line and electrocute a utility worker. The Ready.gov power outage page covers the basics of doing this the right way.
If you find yourself running cords to the fridge, the sump pump, and half the kitchen every storm, it’s probably time to consider a transfer switch, which we explain in full here. It lets the generator feed selected circuits safely without a single extension cord.
Where to go from here
Start by finding the amp rating inside your own fridge and doing the quick multiplication. That one number tells you whether a 1,000-watt or 2,000-watt unit is the right call, and it takes about thirty seconds.
If your outage plan is growing to include air conditioning or the whole house, don’t try to stretch a small inverter to cover it. Look at sizing a generator for central air conditioning or a permanently installed system in our whole-house standby generator guide. But for keeping the groceries cold through the next storm, a good 2,000-watt inverter and a solid extension cord will get you there without drama.
