How Much Energy Does My Freezer Use?

Energy labels from A-G for freezers.

Learn how to calculate the energy consumption of your freezer!

There’s plenty of reasons why you would want and need your freezer to be running at optimum efficiency. Having a freezer that doesn’t use energy effectively is not only bad news for the environment, but for your utility bills too. It’s also very easy to forget that when you buy a new freezer, the price of the unit isn’t the only financial commitment you’re making. You’re also committing to how much it costs to run!

In this guide, we’re going to look at how you can calculate the energy that your freezer uses. A freezer is a wise investment for your home, helping you save money on your food expenses when used properly. By calculating the energy consumption of different freezer models, you can ensure you get the best return on your investment.

Energy Labels

All freezers bought in the UK are legally required to display an energy label. Energy labels across various appliances are calculated using the same standardised tests. This ensures that you can easily compare any model on the market.

The energy label found on a freezer will display a calculated kWh/annum. This is the average amount of energy consumed per year by your freezer, according to their standardised test.

This result is extremely helpful when comparing models against each other. For example, you’re more likely to want to buy a 180kWh/annum freezer of the same specifications than a 200kWh/annum freezer. Lower energy consumption results in lower annual energy costs, as well as being better for the environment.

New Energy Label and Features

However, the calculated energy consumption per year will differ from actual average household use. This is because it doesn’t take into account factors such as:

  • Differences in outside temperatures
  • How often the door is opened and closed
  • How much capacity is filled
  • The addition of new produce
  • The ambient temperature settings
  • The level of frost build-up

For a more accurate measurement, read on to learn how to calculate this yourself.

How to Calculate Energy Usage

The measurement used to calculate energy consumption for your freezer, or any other electrical appliance, is kilowatts per hour (kWh), which is equal to the wattage use divided by 1000.

kWh = Watts/1000

Important: Using the wattage listed in your freezers model specifications will give you a highly inflated result.

This is because the calculation will assume that your freezer is actively working at full capacity at all times. This isn’t the case though. Once your freezer reaches its set temperature, it doesn’t need to constantly be working at full capacity to maintain it.

How to Calculate Daily Energy Use

To calculate your daily energy use, you first need to figure out how much wattage your freezer uses. There are two ways to calculate this, one being more accurate than the other.

The first way is to check the wattage listed on your freezer’s specifications. This is often found on a sticker on the bottom or back of your freezer. It may also be listed on the manufacturer’s website or within the model handbook. However, the wattage listed is the wattage output when your freezer is at full capacity. In order to get a more accurate calculation of your energy output using this wattage, we suggest that you divide this by 3.

If you want an exact measurement of your freezers energy usage, we would recommend purchasing a power usage monitor plug. You can then use this to create an estimate for your yearly energy consumption.

Example for calculating daily energy consumption:

Our example freezer has a listed wattage of 100. For a more accurate energy consumption result, we first divide this by 3.

100 W / 3 = 33.333 W

This gives us 33.333 watts. We now need to convert this into kWh. This is done by dividing the wattage by 1000.

33.333 W /1000 = 0.0333 kWh

The result of this calculation is 0.0333 kWh. This means that our example freezer uses 0.0333 kilowatts per hour. To calculate the daily energy usage, we just need to multiply by 24.

0.0333 kWh x 24 = 0.8 kWh per day

Our final calculation here is 0.8 kWh, which shows us how much energy has been consumed in one day.

How to Calculate Weekly Energy Use

To measure how much energy your freezer consumes per week, you first need to calculate how much energy is consumed daily. Look at the above calculation to learn how to do this.

Our example freezer uses 0.8 kWh per day. To find the average weekly energy consumption value, we multiply this number by 7.

0.8 kWh x 7 = 5.6 kWh per week

This shows that our example freezer uses 5.6 kWh per week.

How to Calculate Monthly Energy Use

You can calculate your average monthly energy usage by multiplying your daily energy usage by 30. This is the average number of days in a month, and gives a more accurate result than calculating for a 28 day month (4 weeks).

You could also multiply your daily energy usage by the number of days within a specific month. This would give you a more accurate average consumption for that month.

For an average 30 day month energy usage estimate, multiply your daily energy consumption by 30.

0.8 kWh x 4 = 24 kWh per month

This gives an average energy consumption of 24 kWh per month.

If we wanted to calculate the energy consumption for a particular month, January for example, we would multiply the daily energy consumption of 0.8 kWh by the number of days in the month. January has 31 days, so let us multiply by this.

0.8 kWh x 31 = 24.8 kWh

This gives us an estimated energy consumption of 24.8 kWh for the month of January.

How to Calculate Yearly Energy Use

Finally, let’s calculate the average yearly energy consumption of your freezer.

To do this, multiply your daily energy consumption by 365. Our daily energy consumption gave us 0.8 kWh.

0.8 kWh x 365 = 292 kWh per year

Multiplying 0.8 kWh by 365 gave us an overall energy consumption of 292 kWh per annum.

  • Reminder: These calculations are used to calculate an estimate only. Your actual energy consumption may be more or less. This will depend on various factors such as how full your freezer is at any one time, how often you open the door, or the external temperature.

How to Calculate the Cost of Your Energy Usage

The final step is taking the cost of your electricity and multiplying that by your estimated energy usage. This will give you an estimate of how much your energy bill will be.

Let’s take the average price of a kWh in the UK, as of February 2024, which is about 29p per kWh. For a more accurate estimate for your household, please check your current energy tariff.

We have used the above energy consumption calculations to create estimates for energy costs.

  • Daily Energy Cost: 0.8 kWh per day x £0.29 = ~£0.24 per day. 
  • Weekly Energy Cost: 5.6 kWh per week x £0.29 = ~£1.63 per week.
  • Monthly Energy Cost: 24 kWh per month x £0.29 = ~£6.96 per month
  • Yearly Energy Cost: 292 kWh per year x £0.29 = ~£84.70 per year.

Results based on a freezer with a listed specification of 100 W.


  • How much electricity does a freezer use per month in the UK?

When using an average wattage of 100, a freezer will use 24 kWh per month. This equates to an average cost of £6.96 per month, as of 2024.

  • Is 40 kWh per day a lot?

On average, a UK household will use a total of 10 kWh of electricity per day. The average amount of gas used per day is 35 kWh. That totals to 45 kWh energy usage per day. This will depend on the size of your home, home efficiency, and the time of year. Therefore, 40 kWh is within a normal daily energy consumption range.

  • Is it cheaper to run a freezer full or empty?

A freezer will run more efficiently when full. This is because it doesn’t have to work as hard to cool down the internal temperature. It is therefore cheaper to run a freezer that is full.

  • Do old freezers use more electricity?

Yes. Older freezers are much less energy efficient than new models. This means that older freezers will use more electricity, which will reflect on your energy bill.

  • Is it cheaper to run a separate fridge and freezer?

No, in general it is not cheaper to run a separate fridge and freezer. Depending on the size and quality, one appliance is cheaper to run than 2.

  • What uses the most electricity in a home?

Other than heating and cooling systems, water heaters, and lighting (which all use the most electricity), kitchen appliances use the most electricity. We recommend looking for energy efficient models to save you money on your kitchen appliance running costs.

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