How to read an electricity meter
Whichever type you have, the number you want is the whole kilowatt hours — the red digits and anything after a decimal point are not part of it.
Digital meters
A row of digits on an LCD. Write down the numbers from left to right and ignore any digit after a decimal point, and any digit in red or on a red background. Those are tenths and hundredths, and suppliers do not want them.
If the display is blank, press the button beside it — many go to sleep. If it cycles through several screens, the one you want is usually labelled IMP or IMPORT, or is the plain kWh total.
Economy 7 and other two-rate meters
These record two totals: one for the cheap overnight period and one for the rest. You need both. They are usually shown as R1 and R2, or as Low and Normal, and on some meters you press a button to move between them.
R1 or Low is normally the night rate. If you are not sure which is which, note both with their labels and let the supplier match them — guessing swaps your rates and produces a bill that looks wrong in an interesting way.
Dial meters
Older meters have a row of small clock faces. They are read left to right, and adjacent dials turn in opposite directions — so check which way each one is numbered rather than assuming.
Write down the number the pointer has passed, not the nearer one. Where a pointer sits directly on a number, look at the dial to its right: if that one reads 0 to 4, use the number the pointer is on; if it reads 5 to 9, use the number below. Ignore any dial marked 1/10.
Smart meters
A smart meter sends readings automatically, so you should not need to. It is still worth knowing how to read the meter itself — the in-home display is a separate device that can lose its connection while the meter keeps working perfectly.
A smart meter running in “dumb” mode after a supplier switch stops sending readings, and bills go back to being estimated. If your bills say estimated and you have a smart meter, that is usually why.
What to do with the reading
Submit it to your supplier. If the bill was estimated, the period gets rebilled against the real figure, which is the single most common fix for a bill that looks wrong.
Two readings taken a week apart also let you work out your own consumption, and readings taken last thing at night and first thing in the morning give you your overnight base load.
With a usage figure in hand, the electricity cost calculator will tell you what it should cost.