How to Determine an Appliance’s Electric Use

A home appliance actually has two costs. The first and most obvious is the amount you must pay to purchase the appliance. The second, which is a longer-term cost and often the more expensive of the two, is the amount you’ll pay for the energy and/or water that powers the appliance. The more efficient the appliance, the lower your electric bill and the more money you’ll save over time!

To determine how much electricity an appliance uses, you’ll have to do a little math. But first, simply look at the appliance’s label to find its electrical rating. The label is usually located either directly on the appliance, or on its power cord or adapter.

If the label gives the appliance’s electrical rating in watts, you’re in luck. Electric companies use kilowatt-hours (kWh) to determine electric rates and calculate your electric bill. The average national charge is about $.12 per kWh.

One kilowatt is equal to 1,000 watts. So for example, if you use a 100 watt bulb for 20 hours, it will use 2,000 watts, or 2 kWh of energy. Your cost would be $.24 (2 kWh x $.12 = $.24).

If the label shows only the number of amps, simply multiply that number by 120 (volts) to get the number of watts. Then use the formula above to calculate the appliance’s total electric use.

You can also determine an appliances electric use (and avoid doing math!) by purchasing a watt-hour meter. This meter, which costs $25, will tell you exactly how much electricity an appliance uses at any given moment or over a specified time period.