What size generator to run a refrigerator?
A household fridge running at about 200 W (Champion’s chart: 150–400 running watts) needs up to 1,200 W for a moment to start (800–1,200 starting watts). Any generator rated 1,200 starting watts or more runs it; a 2,000 W-class inverter generator runs it with room for lights, phones and a freezer.
How to work it out
- Running total 200 W × (1 + 25% headroom) = 250 W running
- Running total 200 W + biggest start-up extra 1,000 W = 1,200 W → 1,200 W starting
In a power cut, keeping the fridge cold is usually job one. The running load is small; the compressor’s start is what you size for, and the extra headroom is what lets you add a few more things.
Adjust for your project
More options: Headroom
- Running watts
- 250 W
- Starting (peak) watts
- 1,200 W
- Running watts, all together
- 200 W
- Biggest single starting surge (extra)
- 1,000 W
- Running current at 120 V
- 1.7 A
- Start the biggest motor first, then add the other loads one at a time — the generator only has to cover one start at once.
Generator size with other headroom
| Headroom on running watts | Running watts | Starting (peak) watts |
|---|---|---|
| 0% | 200 W | 1,200 W |
| 10% | 220 W | 1,200 W |
| 25% | 250 W | 1,200 W |
| 50% | 300 W | 1,200 W |
What to know about running a fridge on a generator
- You don’t need to run it all day. A closed fridge holds its temperature for hours. Running the generator a few hours at a time saves fuel — your local health authority’s food-safety guidance says how long food stays safe.
- Add a freezer for about 1,000 W of extra start. Champion lists freezers at 100–500 running and 500–1,000 starting watts. Both together are still well inside a 2,000 W generator if they don’t start at the same instant.
- Inverter generators are thriftier at light load. Champion’s 2000 W dual-fuel inverter is rated 11.5 hours at 25% load on its 1.05-gallon tank — right in this range.
- Outdoors, far from the house. CPSC: never in a garage or near open windows, and keep battery CO alarms inside.
Fuel for the night is on how long a generator runs on 5 gallons of gas. For a battery instead of a generator, see how long a power station runs a refrigerator; for the whole house, what size generator to run a house.
Different size? Use the full Generator Size Calculator.
What you’ll need
- Inverter generator (about 2,000–3,500 W)Premium price
Quieter and more fuel-thrifty at light loads than an open-frame generator, with clean power for electronics. Many have a 30 A RV outlet.
See options on Amazon (opens in a new tab) - Battery-operated carbon monoxide alarmBudget price
CPSC advises battery or battery-backup CO alarms whenever a generator is in use. Look for UL 2034 certification and test monthly.
See options on Amazon (opens in a new tab) - Outdoor generator extension cordMid-range price
Lets the generator sit well away from the house. CPSC says to use outdoor-rated cords whose rating exceeds the total load, with all three prongs.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
What size generator to run a refrigerator and a freezer?
About 438 W running and 1,350 W starting, with one compressor starting at a time.
What size generator for a large refrigerator (400 W running)?
At least 1,200 W starting and 500 W running.
What size generator to run a fridge, a freezer and a window AC?
About 1,688 W running and 2,750 W starting.
Other common sizes
- What size generator to run a well pump — 2,500 W running / 4,000 W starting
- What size generator to run a house — 4,550 W running / 4,740 W starting
Sources
- Champion Power Equipment — Generator Wattage Chart (opens in a new tab) — Typical running and starting watts for household, RV and job-site appliances (a manufacturer’s planning chart — your nameplate wins).
- Virginia Cooperative Extension, BSE-301: Estimating Appliance and Home Electronic Energy Use (2020) (opens in a new tab) — Wattage × hours ÷ 1,000 = kWh per day; watts = amps × volts when only amps are listed; a refrigerator runs at full wattage about a third of the time; typical nameplate wattages.
- ENERGY STAR — Certified Televisions data set (on-mode power) (opens in a new tab) — Certified models, on-mode watts, retrieved October 2026: 32 in about 27–36 W; 43 in about 45–78 W; 50 in about 61–90 W; 55 in about 64–114 W; 65 in about 85–135 W; 75 in about 120–176 W.
- U.S. Consumer Product Safety Commission — Portable Generator Hazards (Safety Alert 5123, 2021) (opens in a new tab) — Never run a generator indoors or in a garage, even with doors open; place it outside far from doors, windows and vents; CO alarms; never “backfeed” by plugging into a wall outlet.
- U.S. Consumer Product Safety Commission — CPSC Warns Consumers in Path of Storms to Take Precautions When Using Portable Generators (July 24, 2020) (opens in a new tab) — “Use your generator OUTSIDE your house ONLY, at least 20 feet from your home”; make sure you have working CO alarms.
- OSHA Fact Sheet — Using Portable Generators Safely (opens in a new tab) — Never attach a generator to a building’s wiring unless a qualified electrician has installed a transfer switch; 3–4 ft of clear space around the unit.
- Champion Power Equipment — 3500-Watt Dual Fuel Generator (model 201213) specifications (opens in a new tab) — 3,500 running / 4,000 starting watts on gasoline; 14 h at 50% load on 4.7 gal; 10.5 h at 50% load on a 20 lb propane tank; 120 V 30 A TT-30R RV outlet.
- Champion Power Equipment — 6500-Watt Dual Fuel Generator (model 201077) specifications (opens in a new tab) — 6,500 running / 8,125 starting watts on gasoline (5,850 / 7,325 on propane); 11 h at 50% load on 7.7 gal; 6.5 h at 50% load on a 20 lb propane tank.
- Champion Power Equipment — 2000-Watt Dual Fuel Inverter (model 201230) specifications (opens in a new tab) — 1,700 running / 2,000 starting watts on gasoline (1,530 / 2,000 on propane); 11.5 h at 25% load on 1.05 gal; 34 h at 25% load on a 20 lb propane tank.