How to estimate your energy use

The energy price cap is often talked about as a particular price, based on a 'typical' user. The current energy price cap sets bills at £1,720 per year for a 'typical household' until 30 September 2025. But what does that actually mean for you?

The energy price cap is actually a cap on the unit rates you pay for each unit of energy you use, not the total amount. It only applies to energy customers who have not fixed into a specific tariff, and are instead on a rolling, variable contract.

No matter what tariff you're on, if you know your unit rates and how much gas and electricity you use in a year you can get a much clearer idea of how much your energy bills will be. Learn where to find this below. 

If you don't know your household's energy usage – perhaps because you only recently moved in – you can get a feel for how much your bills might be by thinking about where you fit into the national averages.

Energy prices changed on 1 July 2025: see the latest energy price cap. 

Are you a low, medium or high user of gas and electricity?

Price comparison sites will ask you whether you're a low, medium or high user of gas and electricity. As a rule of thumb:

• Low users are likely to be those in small houses or flats with one or two occupants;
• Medium users are likely to be those in medium-sized houses with two or three bedrooms and two to three occupants;
• High users are likely to be those in larger homes with four or more bedrooms and four to five occupants.

The medium user is the one that the price cap figures are based on. But every household is different. Some of us like cool temperatures while others keep their thermostats high. Some people are at home all day, while others leave their houses empty a lot of the time. And some homes are much better insulated than others. 

So it's always more accurate to estimate your future bills based on your real usage figures rather than average usage. 

When energy suppliers use estimates, you can end up with bills massively overestimated or underestimated. This can mean your direct debit payments don't match up with what you're using, and you can end up with either too much credit on your account (if you've been overpaying) or in debt (if you've been underpaying).  

Estimated energy use figures

The table below shows the figures that energy regulator Ofgem uses to define high, medium and low annual energy usage for electricity, gas and Economy 7 tariffs (which charge different rates for electricity used during the day and overnight). 

Taking these figures into account, here's what low, medium and high users will be paying until 30 September 2025, if they pay for a variable tariff by direct debit at the level of the price cap: 

*Standing charges and unit rates vary by region and supplier. We've expressed them as averages to the nearest penny here but our calculations use multiple decimal places.

Customers who don't pay by direct debit will have slightly different rates.

Find out more about: the energy price cap decrease from July 2025

People on fixed energy tariffs will pay the same rates for the duration of their contract and won't be affected by changes to the energy price cap. 

To see the latest deals available on the market and how they compare to variable rates, head to our guide to how to get the best energy deal.

How to find your actual energy usage figures

If you've been with your energy supplier for a while, and have submitted frequent meter readings, your estimated annual usage should be more accurate. 

When you know your annual usage and you know what your unit rate is, you can get a much more accurate idea of what your annual bills will be.

If you suspect your energy provider is overestimating your usage, look back over your meter readings to find out what you've used in a year. 

To get your actual usage over the last 12 months:

• find two meter readings in your statements submitted approximately 12 months apart, for example one from 1 June 2024 and one from around 1 June 2025 They don't have to be from exactly the same day, but the closer the better 
• subtract the meter reading taken on the date last year from the one taken on a similar date this year. 

This will give you a concrete figure for exactly how many units you've actually used in a 12-month period. This can be very useful for doing your own assessments of how much your energy is likely to cost. 

Electricity meters record your usage in kWh. Multiply this by your unit rate (for many households this will be around 25p per kWh) to find out what this would cost you over the year. 

Don't forget to add on your standing charge, multiplied by 365, as you pay this each day.

Calculating usage from gas meters

Gas meters record cubic metres or feet. There's a calculation that needs to be done to convert this into kWh. If you take a look at your energy statements, they will show how your provider converts these into kWh in order to establish your unit rate. If you put your annual meter reading figure through the same equation, you'll find out how many kWh of gas you've used in a 12-month period.

It should be something like this: 

• If your annual meter reading is in cubic feet, multiply by 2.83 to convert to metres. You don't need to do this if your meter reading is already in cubic metres. 
• Multiply by 1.02264.
• Multiply by the 'calorific value' (this will be shown on your gas bill).
• Divide by 3.6 to work out your kWh figure.
• You can then multiply the kWh figure by your pence per kWh rate (for many people this will be around 6p per kWh).
• Don't forget to add on your standing charge, multiplied by 365, as you pay this amount each day.

How to work out the running cost of appliances

If you know the wattage of a household appliance - the amount of energy it needs to run - you can work out how much it will cost to use that appliance for a period of time. You'll usually find the wattage shown on the bottom or back of the appliance.

For example, if your washing machine is 2,000 watts (2kW) and you run it for an hour, it will use 2kWh. A kWh measurement is the number of kilowatts you'd need to run something for an hour. So if you're paying 25p per kWh for your electricity, running your washing machine for an hour will cost you 50p (2 x 25p).  

You can also consult our guide on how much your appliances cost to run to see average figures for most household appliances.