What size generator do I need to run a refrigerator and freezer?

Saving the food is the first job in most outages. A full fridge and freezer can be worth hundreds of dollars, and neither one needs a big generator.

How many watts does a fridge or freezer use?

It depends a lot on age. Newer fridges use far less than the old figures you'll see quoted.

Appliance	Running watts	Starting watts	Source
Fridge (modern)	150–400	800–1,200	Champion
Freezer (upright or chest)	100–500	500–1,000	Champion
Fridge or freezer (older chart)	700	2,200	Honda
Mini fridge	50–100	400–600	Champion

Our calculator uses 400 running and 1,200 starting watts for a fridge, and 300 running and 1,000 starting for a freezer. Those sit at the high end of Champion's ranges for today's models.

Fridges and freezers don't run all the time. Their compressors cycle on and off to hold the temperature. So a fridge might draw 400 W for a while, then almost nothing. That's good news for fuel.

A worked example: fridge, freezer, lights and chargers

• Running: 400 (fridge) + 300 (freezer) + 100 (lights) + 15 (Wi-Fi) + 80 (phones/laptop) = 895 W
• Biggest surge: the fridge, 1,200 − 400 = 800 W
• Starting: 895 + 800 = 1,695 W
• With 20% headroom: about 1,100 running and 2,050 starting watts

That fits a 2,000 W class generator, with a little room to spare. The calculator above is set up with this list.

Just the fridge and freezer? Running is 700 W and starting is 1,500 W. With headroom, that's 850 running and 1,800 starting.

What if both compressors start at once?

It happens. Both cycle on their own, and now and then they'll kick on together. Then you need both surges at once: 700 + 800 + 700 = 2,200 W for a moment. A 2,000 W generator may trip its breaker if that happens. A 3,000 W unit won't blink. If you want a small generator, keep other loads light and it will almost always be fine.

What size generator for two refrigerators and a freezer?

• Running: 400 + 400 + 300 = 1,100 W
• Starting (one at a time): 1,100 + 800 = 1,900 W
• With 20% headroom: about 1,350 running and 2,300 starting watts

A 2,500–3,500 W generator handles this. If a fridge in the garage is old, size up: it could need 2,200 W to start by itself.

Fridge plus a TV, a furnace or a window AC

People rarely want just the fridge. Here's how common pairs add up, using our calculator's figures:

Fridge plus...	Running W	Starting W	Look for
TV, lights and Wi-Fi	665	1,465	2,000 W
Freezer and TV	850	1,650	2,000 W
Furnace fan (1/3 HP)	1,100	2,200	2,500–3,000 W
8,000 BTU window AC	1,150	2,400	About 3,000 W
1/2 HP sump pump	1,400	2,550	About 3,000–3,500 W

In each case the starting figure is the running total plus the single biggest surge. The furnace and AC rows come out higher because their surges are bigger than the fridge's.

How to find your fridge's real numbers

1. Find the label. On most fridges it's inside, on a side wall near the crisper drawers or at the top. On some it's behind the kick plate at the bottom. On a chest freezer, look on the back or side.
2. Read the amps. Multiply by 120 for watts. A fridge rated 6 A could draw up to 720 W. The label figure is a maximum, so everyday running is usually lower.
3. Starting watts are rarely listed. Plan on about three times the normal running watts.

A quick way to see real use: plug the fridge into a plug-in energy meter for a day, if you have one.

Keep the food cold with less fuel

• You don't need to run it all day. You can run the generator a few hours at a time, then shut it off. A closed fridge holds its cold for hours, so keep the doors shut.
• Run the generator at a light load. An inverter generator can idle down when the fridge isn't running, which saves fuel and noise.
• Freeze water bottles before a storm. They help hold the cold when the generator is off.

A battery option for a fridge

A portable power station can run a fridge through a short outage with no fuel and no fumes. You size it in watt-hours, not just watts. See can a portable power station run a refrigerator?

Plugging in

Fridges and freezers use normal 120 V plugs. Run a heavy-duty outdoor extension cord from the generator to each one. Don't use thin indoor cords. Never backfeed the house through a wall outlet. If you want the fridge on its home circuit, have a licensed electrician install a transfer switch or interlock.

Safety: Run it outdoors only, 20+ feet from the house, away from windows and doors. Read our carbon monoxide guide.