Appliance Running Cost Calculator

Use this general calculator when you know an appliance's wattage. It converts watts into kilowatt-hours and then applies your electricity unit rate.

Appliance power (watts)Hours per sessionSessions per weekElectricity rate (pence/kWh)

Energy per session1.000 kWh

Cost per session£0.26

Weekly£1.84

Monthly estimate£7.98

Annual estimate£95.80

Formula: watts ÷ 1,000 × hours × electricity rate. This is an estimate; cycling appliances may draw less than their full rated power for part of the session.

What the result means

For cycling appliances such as fridges and dehumidifiers, rated wattage can overstate average consumption.
A plug-in energy monitor is useful when you need a measured figure.
Standing charges are excluded because they are payable regardless of the individual appliance.

Related guides

Read more about the topics covered by this calculator:

How to calculate appliance electricity cost

How this calculator works

Formula

Watts ÷ 1,000 × hours × electricity rate (pence/kWh) = cost in pence

Inputs

Appliance power in watts (from the label)
Hours of use per session
Sessions per week
Electricity unit rate in pence per kWh

Outputs

Energy per session (kWh)
Cost per session
Weekly cost
Monthly estimate
Annual estimate

Assumptions

Rated wattage is used as the power draw.
For appliances that cycle (fridges, dehumidifiers), rated wattage can overstate average consumption.
Standing charges are excluded.

Example calculation

A 1,000W appliance running 1 hour at 26.32p/kWh: 1,000 ÷ 1,000 × 1 × 26.32 = 26.3p.

Tariff source

Default rates from Ofgem. Override in calculator.

Limitations

A plug-in energy monitor provides a more accurate measured figure.
Some appliances (fridges, freezers) cycle on and off; rated wattage is the peak draw.
Standing charges and fixed daily charges are excluded from this calculation.