Electric Rate Calculator

Calculating Electricity Use

Electricity usage for household items varies, depending on the watt rating and length of time operating. To determine the electricity usage of your electrical item, use the following steps:

1. Find the wattage rating. This is usually on a small metal plate on the back or bottom of the item. Some items list the volts and amps instead of watts. To obtain the watts, simply multiply:

(Volts x Amps = Watts)

2. Estimate the hours per month the item is used.
3. Using the formula below, calculate the approximate number of kilowatt-hours for each item.

watts x hours of operation = kWh
1,000 watts

Example: A 1,500 watt microwave oven with estimated use of 10 hours per month (20 minutes per day).

1500 watts x 10 hours/month = 15 kWh
1,000 watts

4. By multiplying the number of estimated kilowatt-hours used per month by the price per kWh, you can determine the approximate operating cost per month of your electrical item.

kWh per month x price per kWh = cost per month

Example: 15 kWh per month x $.17 per kWh = $2.58 estimated cost per month.

5. The cost per kilowatt-hour of electricity for residential accounts is made up of delivery and supply components.

For current residential delivery rates, visit our Residential Rates page.

If you have chosen a competitive electricity supplier, check your supply rate on your bill or with your chosen supplier.
To obtain current Standard Offer electricity supply charges, go to the Maine Public Utilities website.

The U.S. Department of Energy also offers information about Estimating Appliance and Home Electronic Energy Use.