How many watts does a refrigerator use? Read it off the yellow label

The number you want is not on the nameplate on the back of the fridge, which lists a maximum amperage, and it is not the compressor’s running watts, which the maker does not publish. It is on the yellow EnergyGuide label, stated as kilowatt-hours per year, and one division turns it into the figure a backup battery is sized from. The sizing itself, with a runtime table and ranked units, is on the battery backup for a refrigerator page.

The method

Kilowatt-hours per year divided by 8,760 hours in a year is the average draw in kilowatts, and times 1,000 is watts. The result already includes the compressor cycling on and off, the defrost heater, the fan and the light, because the test that produces the label runs the whole appliance for days at a 90 degree room temperature with the door closed. It is the most honest single number a refrigerator has.

Model (ENERGY STAR listing)	Type	Volume	Annual use	Average draw	Per day
Frigidaire FFHI1835V	Top freezer	18.3 cu ft	453 kWh	52 W	1,241 Wh
Whirlpool WRFF3336S	French door	30.5 cu ft	645 kWh	74 W	1,767 Wh

Source: the ENERGY STAR certified refrigerators dataset, read September 10, 2026. The same dataset lists every certified model since the mid-2010s; search yours by model number, and if it is older than the dataset, the label on the inside wall of the fridge carries the same figure.

What raises the number

The label test is a closed door in a warm room. A kitchen that is opened forty times a day, a fridge packed warm after a grocery run, or an outage in August when the room is 85 degrees all push the average up. There is no published multiplier; the honest approach is to treat the label figure as a floor and add margin in the battery, not in the arithmetic. Twenty percent covers most kitchens.

Why the small number needs a big inverter

The compressor is a capacitor-start motor, and when it kicks on it draws locked-rotor current, typically five to seven times running current, for a fraction of a second. On a 100 to 150 W compressor that is a brief spike toward a kilowatt, which is why a battery with a 300 W inverter that holds plenty of watt-hours still will not run a fridge. Makers do not print the compressor’s locked-rotor figure on the EnergyGuide, so size the inverter with margin: 1,800 W continuous and 3,000 W surge is comfortably above any residential compressor. The general mechanism, and why some motors spike more than others, is in running watts versus surge watts.

From watts to a battery

At 52 W average, a day is about 1,240 Wh at the outlet. Inverters lose roughly 15% turning battery watt-hours into outlet watt-hours, so a day of the top-freezer wants about 1,460 Wh of usable battery, and the French-door about 2,080 Wh; the usable capacity guide explains where those watt-hours go. A 1 kWh class power station is most of a day; a 2 kWh unit is a day and a half to two days.

A chest freezer runs on the same method at about half the draw; the chest freezer wattage guide has three sizes.

The clock that matters more than the battery

USDA guidance is that a closed refrigerator keeps food safe for about 4 hours without power, a full freezer for about 48 and a half-full freezer for about 24. A battery extends the refrigerator’s window to a day or two, which is the difference between a cleaned-out fridge and an inconvenience. Keep the door closed regardless, and put a thermometer inside: 40 degrees Fahrenheit is the line.