Calculate appliance electricity cost
Enter the appliance wattage, how long it runs, and your electricity unit rate. The calculator converts watts into kWh and estimates the running cost.
Tumble dryer using 45.00 kWh over 30 days.
Electricity cost formula
The calculation has three steps: convert watts into kilowatts, multiply by time to get energy use, then multiply by the unit rate.
kilowatts = watts ÷ 1,000
kWh used = kilowatts × hours used
cost = kWh used × unit rate
This calculator estimates usage cost only. It does not include the daily standing charge, because standing charges apply to your whole electricity supply, not one appliance.
Example appliance running costs
Actual wattage varies by appliance, model, setting and age. These examples show how the calculation works.
2,000W heater
Used for 1 hour at 26.11p/kWh: about 52p.
1,500W dryer
Used for 1 hour at 26.11p/kWh: about 39p.
100W device
Used for 5 hours at 26.11p/kWh: about 13p.
Where to find appliance wattage
Appliance wattage is often shown on the product label, plug, manual, manufacturer website or energy label. If it shows kilowatts instead of watts, multiply kilowatts by 1,000 to get watts.
- Watts: 1,500W means 1.5kW.
- Kilowatts: 2kW means 2,000W.
- Variable appliances: washing machines, ovens and heat pumps may cycle up and down during use.
- Smart plugs: a plug-in energy monitor can measure real usage more accurately.
How appliance cost connects to your energy bill
Appliance costs explain the usage part of your bill. Your full electricity bill also includes standing charges and may be affected by tariff type, payment method, region and meter type.
Estimate your full energy bill
Use annual gas and electricity usage, unit rates and standing charges to estimate your whole bill.
Ways to use this result
Once you know what an appliance costs to run, you can decide whether changing habits, switching settings or replacing an appliance is worth it.
- Compare a tumble dryer cycle with air drying.
- Estimate how much a heater costs during winter evenings.
- Compare old lighting with LED lighting.
- Check whether an appliance is a major contributor to your bill.
Estimate lighting savings
Compare old bulb wattage with LED wattage and estimate the payback period.
Electricity cost calculator FAQs
How do I calculate appliance electricity cost?
Divide watts by 1,000 to get kilowatts, multiply by hours used, then multiply by your unit rate.
What is a kWh?
A kWh is one kilowatt of power used for one hour. It is the unit shown on electricity bills.
Does this include standing charges?
No. It estimates appliance usage cost only. Use the energy bill estimator for standing charges.
Why does my actual appliance cost differ?
Appliances can use different power at different settings, cycles and temperatures. The calculator is an estimate based on the wattage and hours you enter.