Even during a power outage, we need a refrigerator and freezer. In such emergencies, we use need a generator to power our fridge. The key question for everybody who wants to use a generator to run a fridge is this:
What size generator do I need to run a refrigerator and freezer? How many watts does a refrigerator use?
Usually, it’s very easy to figure out how big a generator you need to power electric appliances. Just check the wattage, and get a generator that produces the same running wattage. When adequately sizing a generator for a refrigerator and freezer, things become more complicated because the fridge needs to start up every few minutes. That means that we have to account for starting wattage.
Here’s the deal:
Peak watts for a refrigerator and freezer can be 3-4 times higher than running wattage. That means that even though your refrigerator and freezer run on 700W, you can’t get a 700W running wattage generator. Yes, such a generator might run a fridge, but it won’t be able to start it up. You’re going to be left with a too-small generator and a flooded fridge.
Here’s how to solve this without guessing something like ‘Can a 1,000-watt generator run a refrigerator’:
You need to figure out both two specifications for your electric appliance:
- Running watts of the refrigerator and freezer. Could be anywhere from 50W to 1,500W.
- Starting watts of the refrigerator and freezer. Could be anywhere from 200W to 6,000W.
Based on this, you will know exactly what size generator you need to run your fridge in the event of a power outage.
To help you out, we have made a list of refrigerator and freezer starting and running wattages. It covers all kinds of refrigerators, including french door refrigerators, side-by-side refrigerators, top freezer refrigerators, bottom freezer refrigerators, mini-fridges, and even freezerless refrigerators (fridges without a freezer).
Example: A standard refrigerator runs of 700W and it has an additional 2,200W starting wattage (that means the total starting wattage is 2,900W). Will a 2,000W generator run this fridge? It won’t. But a 3,000W generator will.
Let’s look at how many watts do different sizes of refrigerators and freezers need. Based on this, we will be able to choose the right size generator; we even recommend some for the most common fridge wattages.
Running And Starting Watts Of Refrigerators/Freezers
Running wattage of fridges ranges from 50W to 1,500W. More importantly, starting wattages of refrigerators and freezers range from 200W to 6,000W.
Here is the full list of fridge wattages. Check how many running watts and peak watts does your fridge have:
| Refrigerator And Freezer: | Running Watts: | Starting Watts: |
| Small Mini Fridge | 50 watts | 200 watts |
| Standard Mini Fridge | 75 watts | 300 watts |
| Big Mini Fridge | 100 watts | 400 watts |
| Small Energy Star Fridge | 132 watts | 528 watts |
| Standard Energy Star Fridge | 192 watts | 768 watts |
| Big Energy Star Fridge | 250 watts | 1,000 watts |
| Small Fridge | 400 watts | 1,200 watts |
| Standard Fridge | 700 watts | 2,900 watts |
| Big Side-By-Side Fridge | 1,000 watts | 4,000 watts |
| Biggest Fridge | 1,500 watts | 6,000 watts |
As you can see, refrigerators and freezers require quite a lot of electrical power to run. Even more importantly, they need a huge amount of start-up power just to start. If you have a rotary compressor refrigerator, it will continuously start and stop every few minutes.
To figure out how much running wattage does your refrigerator and freezer have just check the specification label. It’s usually located on the back of the fridge; you will have to move it a bit to check.
How to figure out how much start-up wattage does your fridge require?
Very few fridges have the start-up watts specified on the label. In most cases, you will have to make a ‘best guess’ of how much initial power they need.
The rule of thumb for refrigerator generator sizing is to multiply the running watts by 4 to get starting watts. Here’s how you calculate that:
Starting Watts = 4 × Running Watts
That means that 1,000W running watts will likely have about 4,000W starting watts. That means you will need at least a 4,000W generator to run such a refrigerator and freezer without problems during a power outage.
Let’s look at what generators you can use to power your fridge:
What Size Generator Do I Need To Run A Refrigerator And Freezer?
When choosing the right size generator for a refrigerator and freezer, you can omit to check the running wattage. What really matters is the starting wattage of a generator.
Example to illustrate why: A 2,000W generator will produce 2,000W starting watts and 1,600 running watts. A refrigerator that requires 2,000W starting watts will run on about 500W running watts.
The running watts are never the bottleneck; the starting watts are.
Using this logic, here are the categories of how big a generator you need for different refrigerators/freezers:
- 1,000W generator for all mini-fridges and most of the eco-friendly Energy Star-rated refrigerators and freezers.
- 3,000W generator for all standard refrigerators and freezers. The 3,000W generator is the most common generator used to power a fridge.
- 5,000W+ generator to power all very big and huge refrigerators and freezers. Not many people have such a big fridge, however.
In more than 95% of cases, you’re looking at 1,000W or a 3,000W generator. Of course, the best thing is to buy the quietest inverter generators. Honda, for example, produces the best overall generators.
Generator Recommendations For Mini Fridges And Energy-Star Fridges (1,000W)
If you need a recommendation, the best 1,000W generator for small refrigerators and freezers is the Honda EU1000I. It’s quiet, multipurpose, and it has an inverter motor.
Honda does make the best generators but they are, of course, of a higher price range. For a cheap 1,000W generator to power a refrigerator and freezer, you might opt for something of lower quality like PowerSmart 1,000W generator.
Generator Recommendations For Standard Refrigerators And Freezers (3,000W)
Most households will need a 3,000W generator to run their refrigerator and freezer.
The top of the line 3,000W generator for refrigerators and freezers is the quietest generator on the market: the Honda EU3000IS. This is one of the most popular generators overall and the best choice to provide the necessary starting watts to start and run a refrigerator and freezer.
If you’re looking for a lower-quality and cheaper 3,000W generator, the Craftsman C0010030 3000i is another option.
This is the 101 of how to adequately size a generator for a refrigerator and freezer. If you have any questions about your specific fridge, use the comments below to illustrate your situation (running and starting wattages of the fridge would be useful), and we’ll try our best to help you out with the calculation.
For general generator sizing, you can also check our article about what size generator do I need for my house here. You will learn about a simple 3-step method of how to size a generator for home.
Thank you.
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I am using hier 320 ltr freezer please suggest me a generator for it
Hello Maqsood, this is a big freezer that usually runs on about 250 watts. The start-up wattage, however, can be as high as 1,000W. So you would need a 1,000W generator. I would suggest using this 1,000W PowerSmart generator; its a gas-powered generator with relatively low noise output and costs about $200. Hope this helps.
I’m using Haier double door i.e. fridge and freezer. Please suggest me a generator for it.
Thanks!
Hello there, the Haier double door fridges run on about 700-1000W watts and need a starting wattage of up to 3000W. So, you would need a generator that can match these 3000 watts. One of the most popular ‘around 3000W’ generators on the market is the WEN 56380i (this one); it has up to 3,800W starting watts and costs about $700. A less reliable but cheaper option would be Champion Power Equipment 200951 (this one); it has 2,500W starting wattage and 1,850W running wattage and costs less than $500. Hope this helps.
I have a 3.5 cubic foot Magic Chef chest freezer in my apartment. The freezer is pretty full. Had 24-hour power outage recently. After the first 12 hours, I moved my frozen food to a neighbor’s freezer. Anyway, now I’m thinking I need an indoor, battery-operated backup generator for my freezer, in case *another* prolonged outage occurs.
I’m still confused about the size of generator I need, though.
According to what I’m reading, my little freezer is rated at about 100 watts. (Someone who tested then posted that the running wattage was about 65 watts.) Also, the manufacturer responded to one customer that the customer’s existing 4000 watt generator “should be able to handle the surge power from the Magic Chief Chest Freezer. The startup power needed is about 1.2 amps while the running draw on this unit is about .8 amps.”
Can you give me an idea of the size of generator I would need to provide 24 hours of power to my freezer, assuming that’s possible? Also, since I’m in an apartment, I’m assuming it would need to be battery operated.
Hello Dallas, sorry to hear about the power outage. When you say you need a battery-operated generator, that simply means you need a big battery. You can think of a battery, by itself, as a generator of electricity.
Now, you need to calculate the size of this battery-powered generator, hence the size of a battery. So, let’s say that the running wattage of your freezer is 65W. You would need to supply that electricity for 24 hours. Here’s how you calculate the minimum battery capacity you need: 65W × 24h = 1,560 Wh. So, you need a battery with at least a 1,560Wh capacity. Battery sizes are usually measured in amp-hour (Ah). If you get a regular 12V battery, it should have at least 130Ah capacity. In practice, 200Ah 12V battery would be perfect for running a little 100W rated freezer for at least 24 hours.
Something like this Renogy 12V 200Ah battery would be suitable in the event of a 24 power outage. Hope this helps.
I have a new GE 25 cu inch side-by-side and a few years old Frigidaire standard 19 cu inch refrigerator, and the 3000W Honda inverter generator WILL NOT start either fridge. The Honda generator is rated at 2800W startup, so food for thought when selecting a generator. Years ago I had a Craftsman 5500W (loud) generator, with a 4200W startup rating, and it barely started a 26 cu inch side-by-side Frigidaire fridge. Refrigerators take a lot of startup due to age as well, and be mindful of the power loss using an extension cord.
Hello Raven, some big refrigerations can have very high wattage demands, yes. Start-up wattage can surpass 3,000W.
Quiet running is not my concern. My concern is not gassing up the neighborhood by running a gas powered generator.
Can you recommend a battery power source that would provide enough start-up power for two 25 foot side by side refrigerator freezers?
And if the two units are not close together I presume that would create an additional start up power-up issue?
The unit does not have to be solar powered, my idea was to use the power grid to charge the back-up battery power source, and then periodically top off the battery.
Hello there, battery power sources are called portable power stations. The EF ECOFLOW Delta Max (this one) is generally considered one of the best portable power stations; it has 2,400W max. wattage. That’s enough for any refrigerator and freezer. Hope this helps.
Hello I have a fridge that provides the following info
Amps 3.3
Volts 115
Hertz 60
Would you recommend a 1000w or 2000w solar powered portable generator?
Hi there, alright, 3.3A x 115V = 380W. So, the max. running current of your fridge is 380W. Most likely, the start-up wattage is below 1,000W so a 1,000W solar portable generator should suffice here.
Thank you for very much for informative article. And if you could answer a specific question I’d really appreciate it. I have a WEN inverter generator 2250 and want to run a GE fridge (420 running watts, starting ?), and an older freezer using 1.6 Amps running, starting ?. Would this generator cut it?
Hi Rob, well, WEN 2250 can produce 2250 starting watts and 1800 running watts. The 1.6 amp freezer (usually on 120V) requires a 192 running wattage. So, you have a total of 612W running wattage. WEN 2250 will handle that.
Now, starting wattage is the crucial thing. Given that the running wattage is 612W, the starting wattage is unlikely to be higher than 2000W, let alone 2250W WEN generator can handle. It seems very likely that this generator will cut it.
Hi, thanks for the article. I am looking for a generator for a commercial size walk in freezer.
is there any information I need to find out about the freezer or is commercial size standard and would you have any recommendations?
ideally I would like to spend under 20k.
thank you.
Hi there, well, you need to know the running wattage (on the specs sheet) and, even more importantly, the start-up wattage. The generator you will buy must produce at least those wattages. Commercial-sized walk-in-freezers come in various sizes, and run on anywhere from 500 watts to 5000 watts or more. The start up wattages on these huge freezers can be higher than 10,000 watts.
Example: If your walk-in-freezer has a starting wattage of 5,000 watts, you will need a 5,000 watt or bigger generator. Hope this helps.
I’m looking to run my sub-zero double door (two compressors) fridge off a battery backup. Looking at the comments, can you confirm my math? Looking to run for 6 hrs
8.4amps x 115v= 966 watts x 6hrs = 5.79 kWh
So I need a battery with that capacity? Looking at the Ecoflow options, there isn’t really anything that would work unless I spend a fortune. So my only option is a gas geneartor?
Thank you
Thank you
Hi Tj, alright, the top running wattage is 996 watts, right? If you run it at 100% input, you would require a generator that can provide 966 watts over a 6 hour period, and a total capacity of 5.79 kWh. Your calculation is on point.
Ecoflow portable power stations are expensive, yes. The best option would be a gas generator; these are quite inexpensive if you don’t go for a Honda generator. You would need a bit more than 996W to cover the start-up watts. 2000W would be ideal; you can run it at 50% load to get 1000W. This WEN 56200i 2000-Watt generator is a good option in this case. Hope some of this helps.
Thank you for your reply, your article made things easy to follow! One last question, I got the 8.4amps from the fridge itself under “total amps”. You article states that to be safe, you should take the running watts and x4. Wouldn’t that mean I would require a generator of approx 4,000 watts to cover the starting the fridge?
Hi TJ, you are right about that starting wattage. The x4 is the safest measure. However, in many cases, x2 is more than enough. If not, the better option is to get a surge protector that will lower the initial watts/amps; we should included that in the article, now that I think of it. The 2000W generator will (most likely) be sufficient.
One parameter that is not considered in this article is the draw when the freezer defrost cycle starts. This can ad a considerable additional load to a generator or solar inverter circuit.
Hi Allen, that’s quite true, that is considered as ‘starting wattage’ and can be much higher than the running wattage. Thank you for the input.