What It Costs
31 tools
Every calculator on this site
Heating, cooling & air
Electricity cost calculator
Any appliance, any country — watts and hours in, money out.
Air purifier running cost
The electricity is cheap. The filters are the bill.
Fan running cost
A whole night for less than a penny an hour — with one catch.
Air conditioner running cost
The summer line on the bill, per hour and per season.
Dehumidifier running cost
A small draw that runs for months — which is the whole problem.
Heat pump running cost
The same warmth for a third of the electricity — until it gets very cold.
Space heater running cost
Every 1,500 W heater costs the same. Only the hours differ.
Kitchen & laundry
Air fryer running cost
Cheaper than the oven — but not for the reason people say.
Dishwasher running cost
Cheaper than the sink, and the eco cycle is cheaper still.
Electric oven running cost
Two kilowatt-hours an hour — unless you use something smaller.
Fridge freezer running cost
Small draw, 8,760 hours a year — which is how it adds up.
Tumble dryer running cost
The most expensive thing you switch on in an ordinary week.
Washing machine running cost
Almost all of it is heating water. The rest is rounding.
Tech, standby & units
Device charging cost
A year of phone charges costs less than one coffee.
Amps to watts calculator
The number the breaker cares about, and the one the bill does.
Gaming PC running cost
The 850 W on the power supply is a ceiling, not a bill.
Standby power cost
Watts nobody notices, running 8,760 hours a year.
TV running cost
Pennies an evening — and the box beneath it may cost more.
Watts to kWh calculator
The plate says watts, the bill says kilowatt-hours. This is the bridge.
Big loads
Electric shower running cost
The biggest thing you switch on all day, for the shortest time.
Underfloor heating running cost
Priced by the square metre, not by the appliance.
Electric water heater running cost
Usually the second largest number in an all-electric home.
EV charging cost calculator
Battery, percentage and your tariff — including the loss the car never mentions.
Hot tub running cost
It heats whether anyone is in it or not. That is the whole cost.
Pool pump running cost
Halve the speed and the power drops to an eighth. Really.
Bill planners Pro
Appliance Replacement Payback
Old appliance, new appliance, the price gap and your own electricity price — worked into the year the replacement pays for itself.
EV Charging Log
Every charge in one table — energy added and the rate you paid — totalled across home and public charging, with cost per mile.
Household Appliance Audit
Every appliance in one table — watts, hours and days each — totalled into a yearly cost you can check against the actual bill.
Meter Reading Schedule
A reading date every month, set once, with an email reminder — so estimated bills stop being a thing that happens to you.
Standby Audit Sheet
Every device that is never really off, in one table with its standby draw — totalled into the yearly cost of doing nothing.
Tariff Comparison Sheet
Unit rate, standing charge and your own yearly usage per tariff, totalled — the comparison the headline rate cannot give you.
How do you work out what an appliance costs to run?
Watts × hours ÷ 1,000 × your price per kWh. A 1,500 W heater running four hours a day uses 6 kWh a day. At $0.17 per kWh that is $1.02 a day, $31 a month and $372 a year.
The only two numbers you need are on the appliance and on your bill. Watts are on the rating plate — on the back, the base, or inside the door — and if it is missing, this page has typical figures for nineteen common appliances. Price per kWh is on your electricity bill, and it is worth finding rather than guessing: it ranges from about $0.13 in Canada to €0.35 in Germany, which is nearly a factor of three on the same appliance.
Two things trip people up. Hours means hours actually running, not hours switched on — a fridge cycles, a thermostat-controlled heater cycles. And washing machines, dishwashers and dryers are measured per cycle, because their draw jumps between 100 W and 2,500 W during a programme.
One kilowatt-hour
Every bill, every appliance and every calculator on this site runs on the same unit: a kilowatt-hour — one thousand watts for one hour. A 100 W lamp burning for ten hours. A 2,000 W kettle for half an hour. That is the whole idea.
watts × hours ÷ 1000 × price per kWh = cost
One kilowatt-hour runs
- 24 hoursof a 40 W fridge
- 11 hoursof a 90 W television
- 2.2 hoursof a 450 W gaming PC
- 40 minof a 1,500 W heater
- 24 minof a 2,500 W kettle
- 3.5 milesin an electric car
Every calculator on this site is the same two steps: turn the appliance into kilowatt-hours, then turn kilowatt-hours into money at your price. What changes between them is only how the first step is measured — by the hour for anything with a steady draw, by the cycle for washing machines and dryers, by the battery for an electric car.
The table below is worth a minute. It is the running cost of a day’s normal use, at three prices that bracket most of the English-speaking world.
| Appliance | Typical draw | A day’s use | At $0.17 | At £0.25 | At €0.35 |
|---|---|---|---|---|---|
| LED television | 90 W | 5 h | $0.08 | £0.11 | €0.16 |
| Fridge freezer | 150 W | 8 h running | $0.20 | £0.30 | €0.42 |
| Gaming PC | 450 W | 4 h | $0.31 | £0.45 | €0.63 |
| Dehumidifier | 300 W | 10 h | $0.51 | £0.75 | €1.05 |
| Window air conditioner | 900 W | 6 h | $0.92 | £1.35 | €1.89 |
| Electric space heater | 1,500 W | 6 h | $1.53 | £2.25 | €3.15 |
| Tumble dryer | 2.5 kWh a cycle | 1 cycle | $0.43 | £0.63 | €0.88 |
Read down the left column before the right ones. The gap between a television and a heater is a factor of twenty, and no tariff shopping will ever close a gap that size.
Frequently asked questions
Where do I find how many watts my appliance uses?
On the rating plate: the back of a television, the base of a kettle, inside the door of a washing machine, or the label on a power supply. It may be given as watts, or as volts and amps — multiply those together to get watts. If the plate is gone, the appliance picker on this page carries typical figures with the usual range next to them.
What is a kilowatt-hour?
One thousand watts drawn for one hour. A 100 W lamp for ten hours, a 2,000 W kettle for half an hour, or a 1,000 W microwave for sixty minutes — all one kWh. It is the unit your meter counts and your bill prices, which is why every calculation here ends in kWh before it ends in money.
Why do you ask for my price per kWh instead of using an average?
Because averages are wrong for almost everybody and they go stale. Prices differ by country, by supplier, by tariff and by time of day, and a national average from last year can be 30% out. The country picker fills in a typical figure so the form is not empty — the number that matters is the one on your bill, and you can type it straight in.
Does a device use electricity when it is switched off?
Most modern ones use a little: a set-top box, a games console in rest mode, a television waiting for its remote, every charger left plugged in. Individually it is 1 to 10 W; across a household it commonly adds up to 30 to 60 W running permanently, which is 260 to 525 kWh a year. There is a separate calculator for exactly that.
How do I count something that switches itself on and off?
Use running hours rather than hours plugged in. A fridge draws its 150 W for roughly a third of the day, so count eight hours rather than twenty-four. A thermostatically controlled heater in a warm room may run half the time. If you want the exact answer, a plug-in energy monitor costs less than a month of getting it wrong.
Is the calculation different for gas?
Yes — gas is billed per therm or per cubic metre rather than per kWh, and appliances are rated in BTU per hour rather than watts. The arithmetic has the same shape but different units. Every calculator on this site is for electricity.
One thing off the bill each month
MonthlyOne appliance a month worth measuring or changing, and what it does to the yearly total. No tariff pitches, no prices — the numbers that stay true.
How we calculate this
Worked example
With Appliance Electric space heater, Power it draws (watts) 1500, Hours a day 4, Days a week 7, Country United States (USD), Your price per kWh 0.17, this page works out $31.05 a month ≈ $372.30 a year. That is 6.00 kWh a day · $1.02 a day · $0.26 an hour while it runs
- Electricity used a year2,190 kWh
- Cost a week$7.14
- Cost a year$372.30
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