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Home & garden.

14 Jun 2022

How to read your gas and electricity meters

The different types of gas and electricity meters all work differently and need to be read differently. This is how to read and understand yours.
Marianne Calnan
electricity-meter-reading

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. 

You should take regular meter readings to ensure your supplier is billing you correctly. 

Each one is read slightly differently. Read on to get the details on how they work.

Find out more: Gas and electricity meters explained

Electricity meter types

Single-rate digital electricity meters 

A single-rate meter has one set of numbers to refer to, and measure 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 

Economy 7 (called white meters in Scotland) and Economy 10 meters have two displays or the ability to switch between the two.

They have readings for daytime and night use. The display marked 'low' or 'night' show 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 meters have the capacity to display two readings.
  • Economy 10 meters have an additional display to record the electricity you use during three different time periods instead of two - including daytime use.

Economy 7 and Economy 10 are the two most common time-of-use tariffs. If you're on one of these, you’ll probably have a special electricity meter that provides two different readings (also known as a two-rate meter).  

But this will change, as smart meters become more widespread, special meters won't be necessary. This will enable all homes with smart meters to access time-of-use tariffs. A few firms are offering these already.  

Time-of-use tariffs charge different rates for electricity used at different times of day. For example, a more expensive rate for electricity used at times of peak demand in the daytime, and a cheaper overnight rate. Economy 7 gives seven hours of cheaper electricity, and Economy 10 gives 10 hours. 

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

How to find your electricity supply number

If you're switching electricity suppliers, your new provider will supply electricity using your existing meter and cabling.

If your exact meter can't be located during the switching process - if you live in a new-build property, for example - Which? Switch will ask you for your meter point administration number (MPAN), also known as your 'supply number' or 'S' number.

If you're switching electricity suppliers, your new provider will supply electricity using your existing meter and cabling.  

Should you be unable to locate your exact meter during the switching process - if you live in a new-build property, for example - Which? Switch will ask you for your meter point administration number (MPAN), also known as your 'supply number' or 'S' number. 

This is a unique number that identifies the correct meter at your property and is different to the serial number printed on the meter itself. You will find your MPAN on your electricity bill. 

Look for a large 'S' and a grid of numbers. The bottom row of numbers (13 digits) is all that’s needed to ensure your switch happens as smoothly as possible. If you can't find it, you should contact your current electricity supplier.

Once you've found your MPAN, compare energy prices with Which? Switch. 

Gas meters explained 

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 meters 

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 meters 

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 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 write 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. 

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

How to find your gas supply number

If you're switching gas suppliers and we can't locate your exact meter - if you live in a new-build property, for example - we'll ask you for your meter point reference number (MPRN), also known as an 'M' number. This is a unique number that identifies the meter at your property. 

You can find your MPRN on your gas bill, not on the meter itself. If you have just moved into your home and do not have a gas bill, you can call the National Grid's meter number helpline on 0870 608 1524. 

Once you've found your MPRN, compare energy prices with Which? Switch and start your switch today.

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.