dopecalc

Electricity Cost Calculator

Estimate the daily, monthly, and yearly cost of running any electrical appliance based on wattage, usage hours, and your electricity rate.

W
hrs
$/kWh

About this Calculator

Estimate the daily, monthly, and yearly cost of running any electrical appliance based on wattage, usage hours, and your electricity rate.

Formula & Calculations

Formula

Cost = (Wattage × Hours × Days) / 1000 × Rate
Where:
  • Cost=Total electricity cost in dollars
  • Wattage=Power consumption of the appliance in watts
  • Hours=Daily usage time in hours
  • Rate=Electricity rate in dollars per kilowatt-hour

Assumptions

  • 1 kilowatt-hour (kWh) = 1000 watt-hours.
  • A month is approximated as 30 days and a year as 365 days.
  • Appliance wattage is assumed constant during operation.

Calculation Examples

Example 1

Inputs:Wattage: 1500W, Hours/Day: 4, Rate: $0.12/kWh
Result:Daily: $0.72, Monthly: $21.60, Yearly: $262.80

(1500 × 4 × 1) / 1000 × 0.12 = 6 kWh × $0.12 = $0.72 daily.

Example 2

Inputs:Wattage: 60W, Hours/Day: 12, Rate: $0.15/kWh
Result:Daily: $0.11, Monthly: $3.24, Yearly: $39.42

(60 × 12) / 1000 = 0.72 kWh × $0.15 = $0.11 daily.

Frequently Asked Questions

How do I find my electricity rate?

Check your most recent electricity bill. The rate is typically listed in cents per kWh (divide by 100 to get dollars per kWh). The US average is around $0.12 - $0.15/kWh.

What is a kilowatt-hour (kWh)?

A kilowatt-hour is a unit of energy equal to using 1,000 watts of power for one hour. For example, a 100-watt light bulb running for 10 hours uses 1 kWh.