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How Much is a Kilowatt Hour?

L. S. Wynn
L. S. Wynn
L. S. Wynn
L. S. Wynn

A kilowatt hour is a unit of energy, and the typical way that electricity is measured. A kilowatt (kW) is 1,000 watts (w), and a kilowatt hour refers to the use of a device or a set of devices that use 1,000 watts for one hour. Using a 100 watt light-bulb for 10 hours would equal 1 kilowatt hour (kWh), as would the use of a 10,000 watt machine for 6 minutes.

Kilowatts and Kilowatt Hours

Residential electric meters measure power usage in kilowatt hours.
Residential electric meters measure power usage in kilowatt hours.

A watt or kilowatt is a measure of power, or how much electricity is being used by a device at a particular moment. This is useful information, because it can be used to compare average energy consumption; an 11 watt compact fluorescent light (CFL) bulb might produce the same amount of light as a 100 watt incandescent bulb, making it more efficient. Like knowing the average miles per gallon (or kilometers per liter) that a car gets, the devices can be compared without taking how long they are being used into account.

An energy efficient CFL light bulb.
An energy efficient CFL light bulb.

Energy is a measurement of power over some period of time. Power companies use the kilowatt hour because power use is cumulative. Someone who uses an 11 watt CFL isn't paying for the 11 watts that the bulb uses in any given instant, but rather how much power is used by that bulb over a month. To determine this cost, how many kilowatts a device uses is multiplied by how many hours it is used to get kWh, which are then multiplied by the price of electricity per kWh.

watts ÷ 1,000 = kWh
kWh × hours of operation × rate = cost

Electricity Rates

Power companies measure energy in kilowatt hours.
Power companies measure energy in kilowatt hours.

Electricity prices are measured by kilowatts used in an hour, and the rate tends to fluctuate over time — both over the long-term, as in a week or month, but also over the course of a single day at the wholesale level. In some countries and regions, prices for electricity can vary based on the time of day in which the power is used; in many other places, however, prices are set by the government or based on the average cost over time. Smart meter technology and "time-of-use" pricing is expected to become more widespread over time, however.

Individuals pay per kilowatt hour for the electricity they use in their homes.
Individuals pay per kilowatt hour for the electricity they use in their homes.

Prices also vary dramatically by region, often based on how much it costs to generate and distribute power, as well as taxes and other charges. In the United States for example, the average residential cost of a kilowatt hour in Wyoming is 6.2 cents and goes all the way up to 25.12 cents in Hawaii.

Electricity Rates in the US

Here are the costs per kilowatt hour by region of the United States in 2010:

Region Average Residential Cost of a Kilowatt Hour
U.S. average 9.83
Pacific Noncontiguous 19.94
New England 14.44
Middle Atlantic 13.80
South Atlantic 10.08
East North Central 9.12
Pacific Contiguous 9.07
East South Central 8.20
West South Central 8.00
Mountain 7.84
West North Central 7.80

Region Definitions:

  • Pacific Noncontiguous: Alaska, Hawaii
  • New England: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont
  • Middle Atlantic: New Jersey, New York, Pennsylvania
  • South Atlantic: Delaware, District of Columbia, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia
  • East North Central: Illinois, Indiana, Michigan, Ohio, Wisconsin
  • Pacific Contiguous: California, Oregon, Washington
  • East South Central: Alabama, Kentucky, Mississippi, Tennessee
  • West South Central: Arkansas, Louisiana, Oklahoma, Texas
  • Mountain: Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming
  • West North Central: Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota

Discussion Comments


I am in Wisconsin, just north of Milawaukee and and unfortunately We Energies charges 13.1 c per kw, not 9.12c as in the list. They also raised their service charge by 75 percent a year ago or so and just this May (2016) both the service charge and electricity cost increased again. I do understand that service charges may have to increase but a 75% increase is very steep especially if they increase it again so soon. Since I rent a one bedroom apartment and use fluorescent and led bulbs as well as other energy savings I end up paying more for the service charges than the energy. At least this time it did not go up by by 75percent, or I would be using oil lamps.


Yeah, we Americans ain't all that. Of course, we're invested and work hard. This includes bullying and butchering one another here, trashing the planet and other lives the world over. So many here think they've hit a home run, when they actually started on third base. Tthem's some hard numbers for crunching our costs.


Alliant energy breaks down your bill to show how much the energy costs to produce the electricity that I use.

It cost $7.94 to produce the electricity we used, but with all the profit, transmission line fees, basic customer charge and tax, my bill for the electricity that cost Alliant Energy less than $8.00 to produce cost me $64 -- a price 800 percent higher than the energy cost to produce it!

Here in Iowa, it seems to me they ask for a rate hike at least once a year and the Iowa Utilities board cuts what they ask for, but always seem to grant some form of rate increase! When you add all the charges on my bill, a kWh costs over $0.14/kWh! According to the chart above, I should be paying an average of $.078/kWh. I guess I am lucky though, because they only charge me a 65 percent mark up on natural gas costs!

The monopoly utilities and the Iowa Utilities Board that is supposed to regulate them should not be allowed to add charges that make the bill more than 50 percent over the cost to them to produce and get it to our doors! How can they in good conscience tell us how to cut back, turn down our thermostats and just plain blame us for the high cost of energy when they mark it up to what should be illegal!


Greed? Would making a profit qualify as greed? Is greed wanting a bank to pay you 5 percent interest on savings instead of 0.5 percent? It's an easy word to use to blame others who work hard, use their brains, and are willing to risk their time, energy and talent to get something more. Its what we Americans have done and continue to do - strive to make life better for ourselves and our children. By the way, if your greedy power company is making so much money, do yourself a favor and do some investing - maybe you could earn 5 percent.


Suppliers offer fixed and variable rates on "supply" of their product to us in Maine. What has been the trend in wholesale costs to them over the past months, and is that trend expected to change?


I pay .14.8 per hour. About 15 minutes down the road, they pay just .06 per hour.


You should see the four county co-op in Pender County, N.C. They are 30 percent higher than duke which provides two miles down the road. It's ridiculous. Four county uses boom trucks and workers to read meters. I guess they need to get the mileage on vehicles to keep them at 6 miles per gallon.


From the could be worse department: we're paying 43 cents per kWh on the Big Island, and it still pencils out to drive a Leaf, but I won't feel like I'm on easy street until our solar panels are up and running.


I am a retired powerhouse (coal and nuclear power) worker. It was an utter disgrace to the U.S. It was a gross waste of money working on powerhouses most of my life. Nuclear was the most wasteful. The required paperwork to run 100 feet of pipe in a nuclear power house was ridiculous. they had to submit pages and pages of a work plan that cost a bunch, in my opinion, then pay a crew for two or three weeks, and then after the work was completed, some engineer would have us remove the 100 feet of pipe. For the entire shutdown i made almost 10,000 dollars for the sake of a 100 foot pipe run, not counting my retirement benefits. And everyone wonders why our electric bills are so high.


electric companies are the same as any business in the U.S.: greed.


Holy cow, that's what I get for living in rural Alaska. Residential customers in my town pay 36 cents per kWh. Industry pays 28 cents per kWh. I *wish* I only had to pay eight cents a kilowatt-hour.


What is wrong with the 'rate' such that you feel you must add charges over that?


I am an employee of an electric distribution utility. We are regulated by the government. There is a plan by the government that we cannot add charges on energy to industrial load except the purchase cost or pass-on kWh cost. Although we are allowed to add charges on demand on top of purchase cost with a very minimal cost per kW.

What would be the best reason to rebut such regulation? The kW charge added on top of pass-on surely won't suffice for the operation and maintenance of the distribution line. A very large part of our revenue will be lost once this is implemented.

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