Gas and electricity meters explained

From smart meters to prepayment meters, Economy 7, Economy 10 and standard meters, here's what you need to know about gas and electricity meters to help you save money on your energy bills.
Sarah IngramsPrincipal researcher & writer
Smart meter display 2 469449

Your gas and electricity meters are the key to getting accurate energy bills. Find out what type you have, how to read your meter if you need to, and what you need to know about different gas and electricity meters to keep your energy costs in check.

Your meters record how much gas and electricity you use and your energy company bases your bills on them. But if you don't have a smart meter, which sends your meter readings to it automatically, and it doesn't get regular meter readings, it will estimate your bills instead.  

Making sure that your energy firm has recent meter readings is the key to getting accurate bills or keeping your direct debit in check. 

If you move home it’s important to read your gas and electricity meters shortly before you move out of your old place, and as soon as you move into your new one, to ensure you only pay for the energy you have used.

Man reading a smart meter

Giving regular meter readings to your energy provider could also help alert you and your energy supplier if there’s a fault with yours. If you’re concerned about this, keep reading to find out what steps to take.

Keeping an eye on your meter will help you to know how much gas and electricity you’re using to help:

  • reduce your energy bills by finding ways to save
  • lower your carbon footprint
  • make it easier to spot if your meters are faulty.

Smart meters make this easier, but it’s still possible to do this without them.

Visit our energy comparison service to use our ratings and expert advice to help you choose the right energy supplier for you. 

How to read your electricity and gas meters

Smart electric meters and smart gas meters should send your meter readings to your energy supplier automatically. 

Many in-home displays (IHDs) – the device that comes with your smart meter that shows how much energy you're using at any one time, and how much it will cost you in pounds and pence – will show your meter readings to save you going outside or into a tight cupboard to access your meter. You may need to scroll through your IHD's menus to do this.

If your smart meter isn’t sending automatic meter readings, or you want to check that it is doing so accurately, you can still take readings manually. How you see the reading depends on the meter. If it’s not immediately visible, you may need to press a button. Check your supplier’s website for instructions or contact it if you’re unsure.

Traditional gas and electricity meters require you to take a reading from the front of the meter. 

The most common types of electricity meters are single-rate digital meters, variable-rate digital meters and dial meters, while the most common types of gas meters are digital metric, digital imperial and dial meters.

Single-rate digital electricity meters

Dial electricity meter

A single-rate meter has one set of numbers to refer to, and measures energy use in kWh. 

To read it, you need to:

  • write down all the numbers before the decimal point, from left to right
  • ignore any numbers after the decimal point (which may be shown in red).

Dial electricity meters

This type of meter shows a series of clock-style dials with numbers from zero to nine. 

Each dial turns in the opposite direction to the dial before it, and some dial electricity meters show a series of clock-style dials.

To take a reading, you need to:

  • start with the left dial and write down the number indicated by the pointer on each dial, moving towards the right
  • if the pointer is between two numbers, record the lower of the two. If the pointer is between nine and zero, record it as nine
  • ignore any red dials.

Variable-rate electricity meters

Variable rate electricity meter

Economy 7 (called white meters in Scotland) and Economy 10 meters have two displays or the ability to switch between them, as they use time-of-use tariffs that charge different rates for electricity used at different times of day. They're also known as two-rate meters. You can read more on these below.

They have readings for daytime and night use. The display marked 'low' or 'night' shows how many units of off-peak electricity you've used, while the display marked 'normal' or 'day' shows how many units of peak electricity you have used. 

To read a variable-rate electricity meter:

  • write down the numbers from both displays
  • ignore any figures in red.

Economy 7 and Economy 10 meters both have the capacity to record two readings but Economy 10 tariffs usually give you three different periods charged at off-peak rates rather than one.

Find out more about how to get the best energy deal.

Gas meters

All gas meters display a single four or five-digit number indicating the number of gas units you've used. You can work out how many units you've used by subtracting your previous reading from an up-to-date one.  

Your supplier converts the number of gas units you've used into kilowatt hours (kWh) and displays this on your gas bill. 

A kWh is a measurement of energy based on how much energy one kilowatt of gas produces in an hour.

Digital metric gas meters

digital metric meter gas

Digital metric gas meters measure gas usage in cubic meters (m3) and usually show 'm' or 'm3'.

You read it by:

  • writing down all the numbers before the decimal point, left to right
  • ignoring any numbers after the decimal point (which may be shown in red).

Digital imperial gas meters

Dial meter gas

This is an older style of gas meter that measures gas in cubic feet (ft3). It will usually show the words 'cubic feet' or the letters 'ft'. 

They can be read by:

  • writing down the four numbers from left to right
  • ignoring any numbers shown in red.

Dial gas meters

This type of gas meter shows a series of clock-style dials with numbers from zero to nine.  

You read it by:

  • starting with the left dial and writing down the number indicated by the pointer, moving towards the right. If the pointer is between two numbers, record the lower of the two. However, if the pointer is between nine and zero, record it as nine
  • ignoring any red dials. 

If you’re not able to read your meters safely, for example because they're not accessible for you, contact your energy firm for help. 

Calculating your gas use

Although gas meters measure the amount of gas used in hundreds of cubic feet or cubic metres, gas bills display your use in kilowatt hours (kWh).  

The industry standard formula for converting cubic measurements to kWh is as follows: 

  • Subtract your current gas meter reading from your previous reading to work out how many cubic meters or feet you have used.
  • If your measure is in cubic feet, multiply by 2.83 to convert to meters.
  • Multiply by 1.02264.
  • Multiply by the 'calorific value' (find this on your bill, or ask your gas supplier).
  • Divide by 3.6 to work out your kWh figure.
  • Multiply the kWh figure by your pence per kWh rate (find this on your bill, or ask your gas supplier) to give the cost of gas used.

Read more about how to work out how much gas and electricity you use.

How to identify your gas meter and electricity meter

Gas and electricity meters

A large collection of images displayed on this page are available at https://www.which.co.uk/reviews/cutting-your-energy-bills/article/gas-meters-and-electricity-meters-what-you-need-to-know-apF6D9d1JKEz

Not sure what type of gas and electricity meters you have? Scroll through the images in the gallery to see the main types of gas and electricity meters in the UK. You can also see more examples in the images above.

You’ll typically find your gas and electricity meters in boxes outside your home, under the stairs, or in kitchen cupboards. If you live in a flat, your meters might be located in a communal cupboard or the basement.

Smart meters

Smart meter in a meter box
Smart meters enable your energy supplier to record your gas and electricity use remotely. So if you have smart meters, you won’t need to send meter readings and your bills need not be based on estimates. 

More than 29 million smart meters have been installed in homes – that’s 55% of all domestic meters. Energy companies are aiming to install smart meters in all homes. You’ll be contacted to arrange your installation, or you can ask your energy firm to book an appointment for you. 

Smart meters enable time-of-use tariffs (where you’re charged different amounts for electricity used at different times of day, similar to Economy 7 tariffs). They can be set up in ‘credit mode’ (if you pay by direct debit or when you get a bill) or ‘prepayment mode’.

Find out more about smart meters including what to do if your energy company can’t read yours.

Traditional electricity meters and gas meters

Woman reading a gas meter

All gas and electric meters should clearly display a set of numbers showing your energy use to date. This might be a digital display, rotating dials or clock-style dials. 

Traditional meters won’t send your meter readings to your supplier automatically. So you’ll need to send them, or contact your energy supplier for help if you are unable to do so.

We recommend you submit meter readings every month, or every three months as a minimum. Take a note of the reading and the date it was taken, or take a photo of your meter. This means you’ll have evidence of the reading in future, just in case.

In the past, energy suppliers had to read your meter every two years, but this was scrapped in 2016.

See other ways save money on your energy bill.

Prepayment meters for gas and electricity

Economy 7 meter dials

Prepayment meters require you to top up before you can use gas and electricity. 

You used to have to go to a shop to top up your card or key, or to buy tokens, and add the credit to your meter by inserting your key, card or tokens into the front of your prepayment meter. But now you can top up remotely with many energy firms, especially if you have a smart prepayment meter. 

Top-up is usually available via your energy provider's website, app, or over the phone. While this does make pay-as-you-go energy much more convenient than it previously was, your electricity or gas can still cut off if you run out of credit, unlike customers who pay by direct debit or when they get a bill.

Find out whether a prepayment meter is right for you, including how to change your prepayment meter to direct debit. Check our energy supplier reviews to see whether they supply prepayment meter customers and if you can get friendly or emergency credit.

Economy 7 meters

Economy 7 meters track daytime and night-time electricity use separately. Coupled with an Economy 7 tariff, they can help save money on power used overnight. They’re often found in homes with electric central heating and storage heaters.

Economy 7 meters provide two readings:

  • One for more expensive electricity used during the day.
  • Another for cheaper night usage. 

Different meters label the two rates in different ways. 

Pricier 'peak' rateCheaper 'off-peak' rate
Day rateNight rate
NormalLow
Rate 2Rate 1

If you have an Economy 7 meter and tariff, make sure you’re making the most of them. Using less than 30% of your electricity during the cheaper night-time hours could mean that you’d pay less on a single-rate electricity tariff (where the charges are the same, regardless of time). 

Check your latest bill or your online account to see how much electricity you’re using at the different rates. To access a single-rate tariff you might need your energy firm to replace your meter or sometimes your two meter readings can be added together.

It’s also worth checking that the clock on your meter is telling the correct time. If not, then you could be using electricity at a higher rate than you realise. 

Reach out to your energy supplier if you’re unsure of your cheaper hours or think your meter’s clock is incorrect.

As smart meters become more widespread, special meters won't be necessary. All homes with smart meters will be able to access time-of-use tariffs. A few energy firms are offering these already.

Find out more about Economy 7 tariffs and how to get the best energy deal.

Economy 10 meters
Man reading an energy bill and frowning

Like Economy 7, Economy 10 meters record how much electricity you use at ‘peak’ and ‘off-peak’ times and Economy 10 tariffs then charge different rates for these. 

But Economy 10 gives 10 hours of cheaper electricity – usually in three blocks. These are often overnight or very early morning, late evening and mid-afternoon.

These meters are also called Heatwise meters and in Scotland are often referred to as ‘white meters’. 

To make the most of your Economy 10 meter, you should try to use as much electricity as possible at the times when it’s cheaper for you. Economy 10 times vary depending on where you live and your energy supplier. Check with your energy firm if you’re not sure when yours are.

Economy 10 tariffs don’t work with existing smart meters, however, and many energy suppliers don’t sell tariffs for them.

Read our tips on how to use less electricity.

What to do if you think your electric or gas meter is faulty

Smart meter in-home display
Unusual bills or meter readings are often the best clue to a faulty meter. 

If you suspect your meter is faulty, record regular meter readings to help prove your case. If you have a smart meter that’s taking daily meter readings then you may be able to track your usage in your online account or app.

You can also try turning off all your appliances and watching your meter. It shouldn’t still be registering significant amounts of energy. 

If you have a smart meter, you can use your in-home display (IHD) to help check your real-time energy use. It isn’t a foolproof way of checking meter accuracy, but it can be a helpful guide if you already have suspicions.   

Gas meters approved under UK law must be within 2% accurate and electricity meters within +2.5% and -3.5% accurate. 

Contact your energy supplier if you think your meter is faulty. Energy firms have a legal obligation to ensure all gas and electricity meters are accurate, so they must investigate.

Meters can be tested at your home or sent away to an independent laboratory. While the actual testing is free, energy suppliers can charge for the cost of removing and replacing your meter. Some reimburse the cost if the meter is found to be inaccurate. Find out more in our consumer rights guide to faulty meters

It’s also worth checking with your supplier that the unique identification number of your meter matches the one shown on your bill. Occasionally these can get muddled, especially if your meter is in a cupboard with lots of others. Look for:

  • Gas meter: Meter Point Reference Number (MPRN) 
  • Electricity meter: Meter Point Administration Number (MPAN) – also known as your 'S' number. Look for a large 'S' and a grid of numbers. The bottom row of numbers (13 digits) is all that’s needed.

You'll only find these on your bills, not on the meters themselves.

You may also need to give these supply numbers to your new energy company if you're switching. If you can't find them, ask your current firm.