One of the questions we get asked most is whether a lit mirror will push up the electricity bill. It is a fair thing to check before you spend. The short answer is that an LED bathroom mirror costs very little to run, usually only a few pounds a year. Here is how the numbers actually stack up, so you can see exactly where the cost sits and buy without second-guessing.

What draws electricity in a lit mirror?

Three parts of a lit mirror use electricity, and they are far from equal:

•     The LED lighting. The strip that lights the mirror uses very little, roughly 10 to 30 watts depending on the size of the glass.

•     The demister pad. The heated pad behind the mirror that keeps it clear is the thirstier part, usually around 30 to 50 watts, but it only needs to run around shower time.

•     The IR sensor. The hand-wave on/off sensor draws a tiny trickle in standby, well under a watt, small enough that it barely registers on a bill.

LEDs are the reason that first figure is so low. They give a bright, clear light at the basin for a fraction of the electricity an old bulb would use. You can see the styles on the bathroom mirror collection.

The maths, in plain numbers

Electricity is billed per kilowatt-hour (kWh), which is 1,000 watts running for one hour. At the July 2026 UK price cap, a unit of electricity costs about 26p per kWh. Your own rate will vary a little by supplier and region, but it gives us a solid figure to work from. A worked example:

•    Your mirror's lights draw 20 watts and you have them on for an hour a day. That is 0.02 kWh, or about half a penny a day. Over a year, roughly £1.90.

•    Run those same lights for two hours a day and you are still only at about £3.80 a year.

The demister costs a similar amount, because it runs for far less time even though it draws more. A 40-watt pad used for 30 minutes a day also works out at about half a penny a day, or roughly £1.90 a year.

Typical yearly running cost

Put the parts together and here is what a lit mirror tends to cost over a year of everyday use:

Most households land somewhere between £3 and £8 a year to run a lit mirror, which is less than a couple of coffees. These figures use the July 2026 price cap rate, so your own tariff will nudge them up or down.

Does the demister cost a lot to run?

This is usually the part people worry about, since a heated pad sounds expensive. In practice it is not, for one reason: you only run it for the short window around a bath or shower, not all day. Left on for 20 to 30 minutes when you need clear glass, it adds a penny or two, not pounds. The trick is simply to switch it off again rather than leave it running, which many of our mirrors let you do independently of the light.

How to keep the cost even lower

A few easy habits shave the number down further:

•    Use the demister only when you need it, around baths and showers, rather than leaving it on all day.

•    Match the light setting to the task rather than running the brightest mode from morning to night.

•    Choose the right size mirror for the space, so you are not lighting more glass than you actually use.

Not sure which light setting suits which job? Our guide to warm vs cool lighting in bathroom mirrors walks through when each one earns its place.

Running cost is not the same as value

It helps to separate what a mirror costs to run from what it is worth to you. A lit mirror gives you proper light at the basin, a clear view after a shower, and a finished look a plain mirror cannot match, all for a few pounds of electricity a year. Every mirror we make is hand-built in Frome and backed by a 10-year guarantee, so it keeps doing its job for a long time. There is more on that on our Made in Britain page.

If you already know the look you want, browse the backlit and 360° edge-lit ranges. Prefer storage alongside your light? The illuminated mirror cabinets run just as cheaply and give you somewhere to keep everything. And if you are still weighing a lit mirror against a plain one, our post on the hidden costs of choosing a non-lit mirror is worth a read.