What Your Appliances Actually Cost to Run

Energy advice is full of anecdotes. The arithmetic is simple enough that you never need one.

The formula

cost = (watts ÷ 1000) × hours × price per kWh

A 2,000 W heater for 5 hours a day at 0.35 per kWh: 2 × 5 × 0.35 = 3.50 a day, about 105 a month. The electricity cost calculator does this per day, month and year so you can compare devices on the same basis.

Where the money really is

Ranked by typical annual cost in a European household:

1. Space heating and cooling — dominant, often more than everything else combined.
2. Water heating — an electric boiler is second on most bills.
3. Fridge and freezer — small draw, but 8,760 hours a year.
4. Tumble dryer — 2–4 kWh per cycle.
5. Everything else — lighting, electronics, chargers.

Standby loads matter less than they used to: a modern TV draws under a watt idle, roughly 3 kWh a year. A set-top box or a games console left in an "instant on" mode can still draw 15–20 W continuously, which is 50 kWh a year and worth switching off.

Finding the wattage

Check the label on the back or underside, the manual, or the manufacturer's spec page. Heating elements draw their rated power constantly; motors and compressors cycle, so use a duty-cycle estimate — a fridge runs its compressor roughly a third of the time.

Measuring instead of estimating

A plug-in energy meter costs less than a month of the savings it finds, and it settles arguments about which device is responsible for a bill.

Making it a habit

Recalculate when your tariff changes; a 20% price rise reorders the priority list. Use the percentage calculator to see what a new unit rate means for your annual total before switching supplier.

FAQ

Is kW the same as kWh? No. kW is power, kWh is energy — power over time.

Does a device use power when off but plugged in? A small amount, usually under a watt for modern equipment.

Why is my bill higher than my calculation? Standing charges, taxes and heating are typically the missing pieces.