Usage and Safety 
electrical appliances

Your electricity use is measured in kilowatt-hours (kwh). One kwh equals 1,000 watts of electricity used for one hour. For example, a 100-watt light bulb that burns for 10 hours consumes one kwh of electricity.


Operating Cost Calculation

We’ve based our calculations in this brochure on an electricity price of 11 cents per kwh (unless otherwise noted). The actual price you pay for electricity may be more or less than 11 cents per kwh , so take that into account in any comparisons or calculating you do. Please take note whether you are paying a fixed or variable price for your electricity supply. If you are paying a variable price, your energy costs will fluctuate. For more information about supply costs, including historical prices, click here. The cost of operating an electrical appliance can be estimated using this formula:

(Watts ÷ 1,000) x Hours Used x 11 cents = Operating Cost

Example: Calculate how much would it cost to operate
a portable electric space heater for four hours with the
heat setting on high (1,500 watts).

(1,500 watts ÷ 1,000) x 4 hours x 11 cents = 66 cents


Wattage: Wattage is usually listed on the appliance nameplate or serial number plate, or in the owner’s manual. If wattage is not listed, you can estimate it by multiplying amps by volts:

Volts x Amps = Watts

For example, to calculate the wattage from the nameplate below:  

 Model No:  ABC12345
 Volts:  120
 Frequency:  60 cycles
 Watts:  75
 Amps:  0.6

120 volts x 0.6 amps = 72 watts


Motors: It’s also good to know that electric motors are commonly rated in horsepower (hp), and 1 hp equals approximately 746 watts. Keep in mind that the figures represented in this guide are estimates from various sources. Your energy consumption will vary, depending on things such as the number of people in your household, seasonal changes, the size, age and efficiency rating of your appliances, and how much your appliances are used.


RG&E Time-of-Use: RG&E has two time-of-use price schedules, I and II. Customers with an annual consumption up to 24,750 kwh will be served under Schedule I. Customers whose annual use exceeds 24,750 kwh are assigned to Schedule II. For the current time-of-use rates and hours, visit For comparison you can base your time-of-use calculations for Schedule I at 8 cents per kwh during peak hours and 6 cents per kwh for off-peak hours. For Schedule II it is 10 cents per kwh during peak hours and 6 cents per kwh for off-peak hours. Peak times are 7 a.m. to 11 p.m. while off-peak hours are 11 p.m. to 7 a.m. and all day Saturday and Sunday.

For the current time-of-use rate information, click here.