Electricity Cost
What an appliance costs to run per day, month and year.
Costing an appliance
Enter the power in watts, the hours it runs per day and your price per kWh; read the cost per day, week, month and year. The presets load realistic figures for the usual suspects โ and the arithmetic is simply watts รท 1000 ร hours ร tariff.
The pattern worth internalising
Anything that makes heat is expensive; almost nothing else is. A space heater at 2 kW for four evening hours costs more than a router, a phone and a fridge combined for the month. Kettles, dryers, ovens and heaters dominate bills; electronics barely register.
Labels overstate the rest: a washing machine's 2000 W rating applies only while heating water, and a fridge cycles โ its averaged draw is nearer 40 W than the 150 on the plate. A plug-in energy meter settles any argument for a few pounds. Find your tariff on a bill, note peak/off-peak splits if you have them, and for the percentage side of a price rise the percentage calculator is next door โ as is the compound interest calculator for what the savings become.
Frequently asked questions
How do I calculate the cost of running an appliance?
Watts รท 1000 gives kilowatts; multiply by hours used and your price per kWh. A 100 W device for 4 hours at 30p/kWh costs 12p a day.
Why is my bill high when everything is switched off?
Heating appliances dominate. Check anything with an element first โ heaters, dryers, immersion heaters โ before hunting phantom standby loads, which are real but small.
Is the wattage on the label what it actually uses?
It is the maximum. Machines that heat intermittently (washers, fridges, ovens) average far less. The presets here use realistic averaged figures.
How much does charging a phone cost?
A few pennies a month. At 6 W for two hours a day it is around 13p a year at 30p/kWh โ phone charging is never where the money goes.