Watt and Wall

Energy calculator

Appliance Running Cost Calculator

Estimate the monthly and annual electricity cost of one appliance using its wattage, your active-use schedule, and your local electricity price.

Your appliance

Estimate one appliance's running cost

All fields are required. Enter a period for decimals; values stay in this browser.

Appliance running cost inputs

Use watts from the label or a measured average.

Maximum 24 hours. Decimals are allowed.

Enter a whole number from 1 to 31.

Use the USD per-kWh rate from your bill or tariff.

Live estimate

Estimated running cost

Updated estimate: $4.20 per month and $50.40 per year.

Estimated monthly cost

$4.20

USD, based on 20 active days

Per active day
$0.211.2 kWh
Per month
$4.2024 kWh
Per year
$50.40288 kWh

At this schedule, the appliance uses about 24 kWh and costs about $4.20 per month. Repeating the same schedule for 12 months gives about $50.40 per year.

Planning estimate only. Cycling, standby power, fees, and tariff rules can change actual cost.

Transparent calculation

Running-cost formula

Wattage is power. Multiplying power by active time estimates energy in kilowatthours (kWh), the unit used to calculate this electricity cost.

Power in kW = appliance watts ÷ 1,000

Active-day energy = power in kW × active hours

Monthly energy = active-day kWh × active days

Monthly cost = monthly kWh × USD price per kWh

Annual estimate = monthly estimate × 12

Worked example

For an 800 W appliance used 1.5 hours on 20 days each month at $0.175/kWh:

Active day
1.2 kWh · $0.21
Month
24 kWh · $4.20
Year
288 kWh · $50.40

Appliance cost questions

Check its nameplate, product label, manual, manufacturer website, or EnergyGuide information. A plug-in electricity meter can provide a measured value for compatible appliances.