Appliance running-cost calculator

Work out how much it costs to run any electrical appliance, from its power rating, how often you use it and your electricity price.

Power rating (W)Hours per use (hours)Uses per weekElectricity price (£/kWh)

Result

Cost per year

Cost per week

How to use this calculator

Check the appliance's power rating in watts — usually on a label on the back or base, or in its manual.
Enter how many hours it runs per use, and how many times a week you use it.
Enter your electricity price per kWh from your bill or tariff.
Read the estimated cost per week and per year.

Assumes the appliance draws its full rated power for the whole time it's switched on — many appliances actually cycle on and off (e.g. via a thermostat), so real usage can be lower.
Assumes a flat electricity price — does not model time-of-use tariffs.

Technical details: what the fields mean

Power rating powerWatts: Power rating in watts, from the appliance's label or manual.
Hours per use hoursPerUse: How long the appliance runs each time you use it.
Uses per week usesPerWeek: How many times a week you use it.
Electricity price pricePerKwh: Your electricity price per kWh — check a recent bill.

Methodology

Energy per week (kWh) = power (kW) × hours per use × uses per week. Cost per week = energy × price per kWh. Cost per year = cost per week × 52.

Worked example

1000W appliance, 1 hour/use, 7 uses/week, 27p/kWh

Inputs: powerWatts=1000, hoursPerUse=1, usesPerWeek=7, pricePerKwh=0.27

Result: £1.89/week, £98.28/year

Practical guidance

For appliances that cycle on and off (fridges, thermostatic heaters), this gives an upper-bound estimate — actual usage is often lower.
Compare a few appliances using this calculator to spot which ones actually dominate your bill — it's often not the ones people assume.

Common mistakes

Confusing an appliance's peak/startup power with its typical running power, which can overstate the cost for motor-driven appliances.
Forgetting standby power for appliances left plugged in — this calculator only covers active use.

Check the label on the back or base of the appliance, or its manual — it's usually given in watts (W) or kilowatts (kW).

No — this calculates active running cost only. Standby power for appliances left plugged in is a separate, usually much smaller, cost.