How much does it cost to run a space heater, or any appliance?
A space heater on all winter, a window unit in August, a dehumidifier running at night: the bill arrives weeks later and never says which appliance inflated it. The calculation takes three numbers: wattage, hours, and your price per kWh.
Mr Deal's calculator
What does an appliance cost you per month?
Pick an example or enter the wattage on the appliance's label, how long it runs, and your state. The price per kWh is your state's official residential average.
Electricity: U.S. Energy Information Administration, Electric Power Monthly, average residential price by state. Thermostat-controlled appliances (heaters, air conditioners) cycle on and off, so full wattage is a ceiling: a plug-in monitor gives the real figure.
What a 1,500-watt space heater costs in every state
Plug-in space heaters are commonly capped at 1,500 watts, a size that suits a standard household circuit. Running five hours a day for a month at full power, it uses 225 kWh. At each state's average residential price for July 2026, published by the U.S. Energy Information Administration:
| State | ¢ per kWh | Per month |
|---|---|---|
| Hawaii | 48.00 | $108.00 |
| California | 33.61 | $75.62 |
| Maine | 32.41 | $72.92 |
| Massachusetts | 30.49 | $68.60 |
| New York | 29.90 | $67.27 |
| Alaska | 28.83 | $64.87 |
| Rhode Island | 28.29 | $63.65 |
| New Hampshire | 26.60 | $59.85 |
| District of Columbia | 25.21 | $56.72 |
| New Jersey | 25.19 | $56.68 |
| Connecticut | 24.16 | $54.36 |
| Vermont | 23.75 | $53.44 |
| Michigan | 23.05 | $51.86 |
| Pennsylvania | 21.72 | $48.87 |
| Maryland | 21.41 | $48.17 |
| Ohio | 19.45 | $43.76 |
| Illinois | 19.22 | $43.24 |
| Wisconsin | 19.06 | $42.88 |
| Delaware | 18.48 | $41.58 |
| Virginia | 17.55 | $39.49 |
| Minnesota | 17.45 | $39.26 |
| Colorado | 17.00 | $38.25 |
| Indiana | 16.73 | $37.64 |
| Alabama | 16.40 | $36.90 |
| Georgia | 16.27 | $36.61 |
| Missouri | 16.09 | $36.20 |
| New Mexico | 16.09 | $36.20 |
| Iowa | 15.99 | $35.98 |
| Oregon | 15.97 | $35.93 |
| Texas | 15.88 | $35.73 |
| West Virginia | 15.78 | $35.51 |
| South Carolina | 15.47 | $34.81 |
| Arizona | 15.38 | $34.61 |
| South Dakota | 15.37 | $34.58 |
| Kansas | 15.27 | $34.36 |
| North Carolina | 15.16 | $34.11 |
| Florida | 15.03 | $33.82 |
| Montana | 14.99 | $33.73 |
| Washington | 14.71 | $33.10 |
| Mississippi | 14.54 | $32.72 |
| Wyoming | 14.36 | $32.31 |
| Oklahoma | 14.35 | $32.29 |
| Arkansas | 14.33 | $32.24 |
| Kentucky | 13.81 | $31.07 |
| Nebraska | 13.78 | $31.01 |
| Idaho | 13.73 | $30.89 |
| Tennessee | 13.71 | $30.85 |
| North Dakota | 13.41 | $30.17 |
| Utah | 13.12 | $29.52 |
| Nevada | 12.77 | $28.73 |
| Louisiana | 12.72 | $28.62 |
| U.S. average | 18.31 | $41.20 |
The spread is the point. The same heater, used the same way, costs 3.8 times more to run in Hawaii than in Louisiana. Before comparing heaters, look at your price per kWh: it is printed on your bill, and it decides everything.
Full wattage is a ceiling, not a bill
A heater or an air conditioner with a thermostat does not draw its full wattage all the time: it switches off when the room reaches the set temperature, then back on. The calculation at full power gives the maximum. For refrigerators, freezers and washers, the yellow EnergyGuide label gives a yearly consumption closer to reality. For everything else, a plug-in usage monitor left on for a few days tells the truth.
When the question is whether to keep an old appliance or replace it, the reasoning is the one in repair or replace: what it costs each year, against what its replacement would cost. And to see how much rising prices cost you overall, line by line, there is your personal inflation rate.
Frequently asked questions
How much does it cost to run a space heater per month?
A 1,500-watt space heater running five hours a day uses 225 kWh a month at full power. At the U.S. average residential price of 18.31 cents per kWh (EIA, July 2026), that is about $41.20 a month. The same use costs about $108.00 in Hawaii and $28.62 in Louisiana. It is a ceiling: a heater with a thermostat cycles off when the room is warm.
How much does a space heater cost per hour?
At full power, a 1,500-watt heater uses 1.5 kWh per hour, so about $0.27 an hour at the national average price. Multiply 1.5 by your own price per kWh, printed on your electric bill, for your exact figure.
How do I find out how much electricity an appliance really uses?
Three sources, from least to most precise. The label or manual gives the maximum wattage. The yellow EnergyGuide label on refrigerators, freezers and washers gives an estimated yearly consumption in kWh. A plug-in electricity usage monitor, placed between the outlet and the appliance, measures what it really draws, standby and thermostat cycles included.
Why is electricity so expensive in some states?
Prices depend on how power is generated, transmitted and regulated in each state, and the spread is wide: in July 2026, the EIA recorded residential averages from 12.72 cents per kWh in Louisiana to 48.00 cents in Hawaii. The same heater can cost several times more to run from one state to another.
Is a space heater cheaper than central heating?
It depends on what it replaces. Heating one room you are sitting in with a space heater, while the thermostat of the rest of the house is turned down, can cost less than heating the whole house. Running a space heater on top of central heating only adds to the bill. The calculator gives the cost of the heater; your utility bill gives the cost of the rest.
Source: U.S. Energy Information Administration, Electric Power Monthly, table 5.6.A, average residential price by state, July 2026.