🔢How to Read Your Electricity Meter

By the What It Costs editorial desk

Every figure on this site is an estimate until you check it against the thing that actually counts your electricity. Doing that takes ten minutes and needs no equipment.

Reading the meter

Digital display. Read the digits left to right, ignoring anything after a decimal point or in a red box. Some meters cycle through several displays — the one you want is labelled kWh, sometimes with a rate number (rate 1 is usually day, rate 2 night).

Dial meter. Five or six small dials, alternating clockwise and anticlockwise. Read left to right; where a pointer sits between two numbers, take the lower one; where it sits directly on a number, check the dial to its right — if that one has passed zero, take the number, otherwise take one lower.

Smart meter. The in-home display gives instant power in watts or kilowatts, which is far more useful for this purpose than the total. Most suppliers also publish half-hourly consumption data in their app or web account, and that is the best free measurement tool most people have.

Measuring one appliance without a plug monitor

1. Switch off everything you can — this works best late at night.
2. Note the meter reading, to the decimal if it shows one.
3. Run the appliance for a measured period: one full dishwasher cycle, one hour of the heater.
4. Note the reading again.
5. Subtract. That is your kilowatt-hours, for that machine, in your house.

For a fridge or anything thermostatic, run it for several hours and divide — you need to capture several compressor cycles for the answer to mean anything.

Finding the household baseline

The same trick with nothing running gives you the number nobody knows about their own home. Late at night, with everything obviously off, note the meter, wait an hour, note it again. The difference is your baseline: standby, the router, the fridge’s average, the alarm, everything permanent.

Typical results are 50 to 150 W. Multiply by 8.76 to get the kilowatt-hours a year — a 100 W baseline is 876 kWh, which for most homes is the second largest single item on the bill after heating, and almost entirely invisible.

The smart meter shortcut

If you have half-hourly data, you do not need to do any of this by hand. Look at a night when nothing was on: the flat line is your baseline. Look at the block when the dryer ran: the height above the line is the dryer. It is the same measurement with the arithmetic already done.

Then check it against the estimate

Take the measured kilowatt-hours to the electricity cost calculator with your own unit rate from the bill. If the measurement and the estimate disagree by more than about 20%, the usual culprit is running hours rather than watts — see how to work out a running cost for the four ways that input goes wrong.