Learn how to calculate your own electric bill for any item and determine approximate savings when implementing an energy saving step.
| Everyone seems to be on the "Going Green" bandwagon lately and they are telling you how much you are going to save. At times, the savings sounds too good to be true. Unfortunately, most of the sales-pitch hype out there can easily become misleading. So what is the average homeowner to do? Time to bring out the accountant in you!  Even if you don't like math here are ways for calculating how much electricity any appliance uses: First let us understand the formula that can be used to figure out the electric bill for anything. So get your pencil and calculator. The first part of the formula is knowing how many watts the appliance uses. The old standard light bulb is the easiest to find out. Just look on the top of the incandescent bulb and it will say: 60, 75 or 100 watts.
With appliances you may have to do an extra step. On the back or bottom of the appliance there will be data on a label, tin plate, sticker, or stamped into the product. If the watts are not shown on this label, then find how many Ampsthe appliance uses.  Data Label On Back Of Appliances Once you know the Amps you can calculate the watts used. The free standing fan on the right uses less than half an Amp, 0.40. Are you still with me? (continued at top) |   120 Volt US Outlets Now since we are plugging all appliances into an electric outlet used here in the United States, the standard Volts for all homes in America is 120 volts. So when you only have the Amps on a hair dryer, (hair dryer example has 12.5 amps on the label) to find out how many watts your hair dryer uses, (or any appliance with their amps) use the formula below: 12.5 amps X 120 volts = 1,500 watts for the hair dryer! The embossed plastic on the back of the printer below has the watts listed: 20W Maximum. So you don't have to use the above formula.
(continued below for the formula to calculate your electric cost) |
So now let us find out the electric cost for these hair dryers. We actually did this for a client who has two hair dryers and four teenage girls. They all wash and dry their hair every night. Each one uses the hair dryer for an average of ten minutes, including the client and her husband. We have a total use of one hour every day with each person using the hair dryer about ten minutes each. Below is how you calculate the electric cost and if the electric bill is really high they may all start to "air" dry their hair or use a towel to hand dry.
Watts X Hours/day X Days/week X Weeks/year divided by 1,000 (one kilowatt hour) X Kwh rate*
1,500 X 1 X 7 X 52 = 546,000 watts/yr. divided by 1,000 = 546 Kilowatt hrs. X .14 Kwh rate = $76.44/yr.
The total $76.44 per year works out to about .21 per day.
Everyone in the family voted for the hair dryer over the towel dry, except the father.
NOTE: If the family had gone on vacation for one week durning the year, then only 51 would be used, not 52 for weeks per year.
Watts X Hours/day X Days/week X Weeks/year divided by 1,000 (one kilowatt hour) X Kwh rate*
1,500 X 1 X 7 X 52 = 546,000 watts/yr. divided by 1,000 = 546 Kilowatt hrs. X .14 Kwh rate = $76.44/yr.
The total $76.44 per year works out to about .21 per day.
Everyone in the family voted for the hair dryer over the towel dry, except the father.
NOTE: If the family had gone on vacation for one week durning the year, then only 51 would be used, not 52 for weeks per year.
Updated Blog Post - Article on EnergyHotwire.com to GoingTrueGreen.com Blog
Bill Lauto, at GoingTrueGreen.com
Environmental Scientist
International Sustainability and Energy Consultant
Contribute your comments!
Bill Lauto, at GoingTrueGreen.com
Environmental Scientist
International Sustainability and Energy Consultant
Contribute your comments!
