What is a 'kWh' (Kilowatt-hour)?

A Kilowatt-hour (kWh) is the universal unit your energy supplier uses to bill you. It simply means running a 1,000 Watt (1kW) appliance constantly for 1 hour. So if you run a 2,000W electric heater for one hour, you have used 2 kWh.

Why do kettles cost so much to run?

Kettles are incredibly powerful (usually drawing 2,000 to 3,000 Watts) so they can boil water quickly. However, because they only run for 2-3 minutes at a time, their actual cost per use is only a few pence. It's high power, but extreme low time.

Which household appliances use the most electricity?

Things that generate heat use massive amounts of power. Tumble dryers, electric fan heaters, immersion water heaters, and electric ovens are the biggest culprits on your bill. In contrast, running a TV or a laptop uses incredibly little electricity.

How do I find out how many Watts my appliance uses?

Look for a small silver or black sticker on the back or bottom of the appliance (or etched into the plastic plug). By law, it must state the maximum power draw in Watts (W) or Kilowatts (kW).

Home Finance & Energy

Appliance Electricity Cost Calculator

Track down the energy vampires in your home. Enter the wattage of any appliance to see exactly how much it adds to your monthly electricity bill.

Appliance Cost

Quick Presets

Current UK Price Cap (approx): 24.5p per kWh

Appliance Power Rating

Check the sticker on your appliance (e.g. 2000W)

Time Used Per Day (Hours)

Your Electricity Tariff (pence per kWh)

Estimated Running Cost

Monthly Cost on Bill£29.81

Daily Cost:£0.98

Yearly Cost:£357.70

This appliance consumes roughly 4.00 kWh per day, adding up to 1460 kWh added to your annual energy statement.

Beating the UK Energy Price Cap

UK electricity prices have surged over the past few years. Understanding exactly where your electricity is going is the fastest way to slash your direct debit and keep more money in your bank account every month.

The "Heating" Rule of Thumb

If an appliance exists to generate heat, it is incredibly expensive to run. Generating heat electrically requires massive amounts of power.

Running a classic 2,000W electric fan heater for just 4 hours a day will add nearly £60 a month to your electricity bill. By comparison, leaving a modern big-screen TV on for exactly the same amount of time costs less than £4 a month.

The Worst Offenders In Your Home

1. Tumble Dryers

They draw up to 2,500W constantly for hours at a time. A single load of drying can cost nearly £1. An air-dryer rack costs £0.

2. Immersion Heaters

These draw a massive 3,000W to heat your hot water tank. Leaving this switched on 24/7 (rather than timing it) is the #1 cause of £300+ monthly winter bills.

3. Old Fridge Freezers

They don't draw much power (usually ~300W), but because they run 24 hours a day, 365 days a year, an inefficient 15-year-old fridge can stealthily add £100+ to your annual bill.

References & Authorities

Electricity & Appliance FAQs

Explore CalZone's Specialist UK Calculators

Plan your home, property, business tax, automotive costs, and daily health metrics with our specialist tools.