What Size Generator To Run Refrigerator And Freezer? (Crucial: Starting Watts)

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 to run a refrigerator?

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:

  1. Running watts of the refrigerator and freezer. Could be anywhere from 50W to 1,500W.
  2. 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.

What Size Generator To Run Refrigerator And Freezer
An average-sized refrigerator and freezer require much more watts to start than to run.

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.

8 thoughts on “What Size Generator To Run Refrigerator And Freezer? (Crucial: Starting Watts)”

    • 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.

      Reply
    • I’m using Haier double door i.e. fridge and freezer. Please suggest me a generator for it.
      Thanks!

      Reply
      • 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.

        Reply
  1. 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.

    Reply
    • 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.

      Reply
  2. 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.

    Reply
    • Hello Raven, some big refrigerations can have very high wattage demands, yes. Start-up wattage can surpass 3,000W.

      Reply

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