Electricity Cost Calculator
The things left on beat the things used briefly.
Work out Electricity Cost. The things left on beat the things used briefly. States the assumption instead of hiding it.
Cost per year
51.14
183 kWh a year · 0.14 a day
Energy is power times time, and the kilowatt-hour is exactly that: a thousand watts for one hour. A 100 W appliance for ten hours uses the same energy as a 1,000 W appliance for one, which is why the low-power things left on all day so often outweigh the dramatic-looking ones used briefly. Standby power is the version of that nobody sees. A few watts continuously is 20 to 50 kWh a year per device, and across a house full of them it reaches a meaningful share of the bill. Grid carbon intensity varies enormously by country and by hour — from under 50 g per kWh where hydro and nuclear dominate to over 700 where coal does. Shifting flexible use to low-carbon hours cuts emissions considerably without cutting consumption at all.
How the Electricity Cost Calculator works
Running cost of any appliance from its wattage and hours of use, per hour, day, month and year, with the carbon that goes with it. Low-power things left on all day routinely outweigh dramatic-looking ones used briefly.
Also known as: how much does it cost to run · appliance electricity cost per year · watts to pounds per hour · standby power cost
Frequently asked questions
How do I calculate electricity cost?
Watts times hours, divided by a thousand, times the price per kilowatt-hour. A 100 W device for ten hours costs the same as a 1,000 W device for one.
What uses the most electricity in a home?
Heating, hot water and anything that makes heat — kettles, ovens, tumble dryers, showers. Electronics are far smaller individually, but there are many of them and they run for far longer.
Does standby power matter?
More than it looks. A few watts continuously is 20 to 50 kWh a year per device, and across a house full of them it becomes a meaningful share of the bill.
What is grid carbon intensity?
The CO₂ emitted per kilowatt-hour generated, which varies enormously — under 50 g where hydro and nuclear dominate, over 700 g where coal does. It also swings hour by hour with wind and solar output.
Does using electricity at different times help?
For emissions, considerably — shifting flexible use to low-carbon hours cuts CO₂ without cutting consumption. For cost it depends on your tariff, but time-of-use pricing makes the two align.
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