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Electricity cost calculator

Choose an appliance or enter its power and running time, add your unit rate, and the energy used and its cost are shown.

Example rate, not today’s price. Enter the unit rate per kWh from your own bill, including VAT.

Appliance 1

Counted for the hours the appliance is not in use. Leave at 0 if it is switched off at the wall.

Cost per year

£27.38

110 kWh a year

  • Per day£0.080.3 kWh
  • Per week£0.532.1 kWh
  • Per month£2.289.13 kWh
  • Per year£27.38110 kWh

The power and times in the list are typical examples. Check the rating plate or energy label of your own appliance.

From your bill

Cost at the rate above£250.00

The standing charge comes on top.
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How it works

Energy is power multiplied by time. A kilowatt-hour (kWh) is 1,000 watts for one hour, so the 2 kW kettle the tool starts with, used for 10 minutes a day, uses a third of a kWh a day. At 25p per kWh that is 8.3p a day, or about £30 a year. Many British kettles draw 3 kW, the most a 13 A plug allows, so it pays to enter the figure on your own appliance.

Use the unit rate from your bill, including VAT. The standing charge is a fixed daily amount that does not change with how much you use, so it is not part of the running cost. The price in the box is an example, not today’s rate, which depends on your tariff, your region and, on some tariffs, the time of day.

Fridges and freezers do not draw full power all the time, because the compressor switches on and off. The rating plate therefore says little about what they use. The energy label gives consumption in kWh per year; divide by 8,760 hours for the average power. 219 kWh a year is the same as 25 W around the clock.

For washing machines and dishwashers the energy label gives kWh per 100 cycles on the eco programme. Divide by 100 for each wash: 70 kWh per 100 cycles is 0.7 kWh. Hotter programmes use more. A heat pump tumble dryer uses less than half the energy of a condenser dryer for the same load.

For heat pumps, heaters and saunas, the time is the time the appliance actually draws power, not the time it is switched on, since the thermostat cycles. A heat pump delivers several times more heat than the electricity it uses, so the figure here is the electricity, not the heat.

Standby is counted for the hours an appliance is not in use. EU ecodesign rules, which Great Britain has kept in its own law, limit what most new appliances may draw on standby to under one watt, but connected devices such as set-top boxes and routers draw more. 5 W around the clock is 44 kWh a year. When charging an electric car, on average around 16% is lost on the way to the battery, so count the kWh taken from the supply rather than what the car reports.

Sources

How the tools are checked