What Actually Uses Electricity in Your Home
Almost everything expensive has a heating element. Standby power is real but small. The appliance-by-appliance numbers, and where the savings genuinely are.
There is one rule that explains most of a household electricity bill: things that make heat are expensive, and things that process information are not.
A kettle uses more power than a hundred laptops. A tumble dryer costs more to run for an hour than a television does in a week. Once you see the pattern, the whole bill becomes predictable, and it becomes obvious which savings are worth pursuing.
The arithmetic
Electricity is billed in kilowatt-hours. One kWh is 1,000 watts drawn for one hour.
kWh = watts × hours ÷ 1,000
At a rate of 27p per kWh, a 3,000 W kettle boiling for three minutes uses 3 × 0.05 = 0.15 kWh, costing about 4p.
The big consumers
Almost everything in this group heats something.
| Appliance | Power | Typical use | Cost at 27p/kWh |
|---|---|---|---|
| Electric shower | 8,500–10,500 W | 8 min | ~32p per shower |
| Immersion heater | 3,000 W | 1 h | ~81p |
| Tumble dryer | 2,500–3,000 W | full cycle | ~55–75p |
| Electric oven | 2,000–3,000 W | 1 h | ~54–81p |
| Kettle | 2,500–3,000 W | 3 min | ~4p |
| Washing machine | 500–2,500 W | 40 °C cycle | ~15–25p |
| Dishwasher | 1,200–1,500 W | eco cycle | ~25–35p |
| Space heater | 2,000–3,000 W | 3 h | ~1.60–2.40 |
The washing machine number is interesting: most of its electricity goes into heating water, not turning the drum. Washing at 30 °C instead of 60 °C can cut a cycle's cost by more than half, which is why it is one of the few genuinely large, genuinely painless savings available.
The constant consumers
These draw little but never stop, which changes the arithmetic entirely.
| Appliance | Power | Annual use | Annual cost |
|---|---|---|---|
| Fridge-freezer | 100–200 W cycling | 200–400 kWh | £54–108 |
| Router | 7–10 W | ~75 kWh | ~£20 |
| Chest freezer | 80–150 W cycling | 250–450 kWh | £68–120 |
| Aquarium / heated tank | 50–200 W | 400–1,700 kWh | £108–460 |
A fridge is only 150 W, but 150 W for 8,760 hours a year adds up to more than the oven for many households. An old, poorly-sealing fridge-freezer is one of the most expensive things in a kitchen and one of the least suspected.
The small consumers
This is where most people look first, and where the least money is.
| Appliance | Power | 4 h/day | Annual cost |
|---|---|---|---|
| LED bulb | 8–10 W | ~£4 | |
| Old incandescent bulb | 60 W | ~£24 | |
| Laptop | 30–70 W | £12–28 | |
| Television (LED, 50") | 60–120 W | £24–47 | |
| Desktop PC | 100–400 W | £39–158 | |
| Games console (in play) | 150–200 W | £59–79 | |
| Phone charging | ~5 W | full charge | ~£0.50/year |
Charging a phone every night for a year costs roughly the price of a cup of coffee. It is not where the money is going.
Standby power: real, but smaller than the folklore
"Vampire" power is commonly estimated at 1–5% of household electricity — meaningful, but not the dominant factor it is sometimes presented as.
More importantly, it is concentrated in a few devices, not spread evenly:
- Set-top boxes and DVRs — often 10–20 W continuously, because they are recording or updating. These are genuinely worth addressing.
- Games consoles in rest mode — 10–15 W, and the setting is usually changeable.
- Older TVs and audio equipment — 5–15 W.
- Modern TVs, microwaves, phone chargers — typically under 1 W. A charger left in the socket with nothing attached draws a fraction of a watt.
Unplugging phone chargers is the advice everyone has heard and the one that saves least. Changing a games console out of rest mode saves roughly forty times as much.
Where the savings actually are
Ranked by how much they move the bill:
- Heating and hot water settings. In most homes this is the majority of energy use. A degree on the thermostat, and the immersion timer, dwarf everything below.
- Wash at 30 °C. Halves the cost of the largest component of a laundry cycle.
- Skip the tumble dryer where possible. One of the most expensive appliances in the house, per hour.
- Replace an old fridge or freezer. Only worth it if it is genuinely old — but a 15-year-old chest freezer in a garage can cost over £100 a year.
- Shorter showers, if electric. An electric shower is the highest-wattage thing in most homes.
- Turn off the set-top box and console rest mode.
- LED bulbs, if any incandescent or halogen remain.
Absent from that list: unplugging chargers, turning the TV off at the wall, and switching the router off overnight. They are not wrong, they are just close to irrelevant next to anything with a heating element.
Working out your own numbers
The wattage of an appliance is on its rating plate — usually on the back, the base, or inside the door. Multiply by the hours you use it, divide by 1,000, and multiply by your rate per kWh, which is on your bill.
The electricity bill estimator does this across multiple appliances at once and shows which ones dominate your total, which is usually the useful output — the ranking matters more than any individual figure.
If you want real measurements rather than estimates, a plug-in energy monitor costs very little and settles arguments about specific appliances quickly. For anything hardwired — showers, ovens, immersion heaters — the rating plate is what you have.