Which appliances actually use the most electricity
Electricity bills feel mysterious because usage is invisible โ but the physics reduces to one rule that sorts every appliance in the house, and a bit of arithmetic the electricity cost calculator does for you.
The one rule: heat costs
Making heat with electricity is expensive; almost everything else is cheap. Moving electrons through a resistive element converts kilowatts directly into warmth โ heaters, water heaters, ovens, dryers, kettles โ while electronics sip by comparison. A space heater draws 2,000 W; the laptop beside it draws 50; the phone charging on the desk, 6. That single distinction explains most of any bill.
The corollary catches people out: small heat beats big electronics. A hair dryer (1,800 W) out-draws a gaming PC at full load; the humble kettle out-draws the television by a factor of thirty while it runs.
The league table
Typical households, roughly in order of annual cost: space heating and cooling where electric (heat pumps mercifully multiply each watt into several watts of heat); hot water; tumble dryer; oven and hob; fridge-freezer โ modest per hour but the only appliance running all 8,760 of them; washing and dishwashing (mostly their heating phases); then lighting and electronics as a long cheap tail. An LED bulb at 9 W costs a few pounds a year; the same light in a 2005 halogen cost ten times that, which is why lighting fell down the table.
Why labels mislead
The wattage on the plate is a maximum, not an average. A 2,200 W washing machine pulls that only while heating water โ the drum motor is a tenth of it. A fridge rated 150 W cycles its compressor and averages nearer 40. Costing a cycling appliance from its label overstates reality several-fold; the presets in the calculator use realistic averaged figures instead, and a plug-in energy meter (cheap, and endlessly informative) settles any specific argument.
The standby myth, resized
Standby power was a genuine scandal in 2005, when set-top boxes idled at 15 W; modern regulation caps most standby below 1 W, so the router-and-telly vampire load of a typical home runs perhaps ยฃ20โ40 a year in total. Worth a smart plug for the worst offenders (older AV equipment, anything warm to the touch while "off"), not worth crawling behind furniture nightly. The exception: game consoles in instant-on modes can idle north of 10 W, which is a real number across a year โ a settings change, not a superstition.
Costing anything in ten seconds
The arithmetic is watts รท 1000 ร hours ร price per kWh. A 2,000 W heater, four evening hours, at 30p/kWh: 2 ร 4 ร 0.30 = ยฃ2.40 a night โ ยฃ72 a month, which is the moment most people take the rule seriously. The calculator runs day, month and year at once; your tariff is on your bill, and off-peak rates (where you have them) make the big movable loads โ dryer, dishwasher, car โ meaningfully cheaper at night. The percentage calculator translates any price-cap headline into your own bill.
Where cutting actually pays
Follow the heat: wash cooler (the heater dominates a wash cycle), line-dry when the weather offers (the dryer is the single most cuttable appliance), batch the oven, boil what you need rather than the full kettle โ small per event, hundreds of events a year. Heating and cooling degrees are the biggest lever of all: one degree of thermostat is several percent of that bill. And ignore advice measured in single watts; the percentages guide is a better use of the evening than unplugging phone chargers. Pikkit has the rest of the household arithmetic.
Sources and further reading
The claims in this guide rest on these references, which were checked when the guide was last updated. Spotted an error? The contact page says how to report it.