Use the watts on the heater’s label, the high setting’s if it lists two. The answer counts those watts for every hour, as if the heater ran at full power the whole time.
For your own rate, divide the electricity charges on your bill by the kWh it lists, then multiply by 100 for cents.
High and low, by the hour and the month
What a space heater costs to run at 17.3 cents per kWh
Setting
An hour
8 hours
24 hours
30 days, 8 hours a day
High, 1,500 W
26¢
$2.08
$6.23
$62.28
Low, 900 W
16¢
$1.25
$3.74
$37.37
Lasko’s 754200 tabletop heater lists 1,500 watts on high and 900 on low. Rounded to the cent.
The watts on your heater
Most of Lasko’s heaters list 1,500 watts, the figure the calculator starts with. Some draw less, such as Lasko’s 400 watt MyHeat Mini. The watts are printed on the heater’s label and in its manual.
Low settings and thermostats
The calculator counts the label’s watts for every hour you enter, so it gives the most the heater can cost. A lower setting uses fewer watts, and Lasko says the Auto Eco mode on its Ellipse heater adjusts output to use up to 50% less energy.
Your own rate
Eight hours at 1,500 watts costs $1.48 at North Dakota’s average for homes, 12.36¢ per kWh from January to July 2026 and the lowest of any state, and $5.55 at Hawaii’s 46.28¢, the highest.
Run a space heater from a wall outlet only, never an extension cord or a power strip. Switch it off and unplug it before you go to bed or leave the room.
Common questions
What does a space heater cost to run all month, day and night?
At 17.3 cents per kWh, a 1,500 watt heater on high for 24 hours a day uses 1,080 kWh in 30 days, about $186.84.
Does a 1,500 watt heater on low cost less?
Yes, by the watts it draws on low. Lasko's 754200 drops from 1,500 watts to 900, so each hour costs about 16 cents instead of 26 cents.
The default rate is the US Energy Information Administration’s average residential price, the heater watts come from Lasko’s product pages, and the safety advice from the CPSC and the NFPA. Checked against published data from CPSC, NFPA, US EIA and Lasko.
See all 5 sources
US Consumer Product Safety Commission, “Keep Warm and Safe This Winter” (January 2026): space heaters directly into a wall outlet, three feet, off when sleeping; portable generators at least 20 feet from the home
National Fire Protection Association, Electric Portable Space Heater Safety tip sheet (2018)
US Energy Information Administration, Electric Power Monthly (released September 24, 2026), Table 5.3: average price of electricity to ultimate customers, 2025 annual residential, and Table 5.6.B: by state, year to date through July 2026
Lasko product pages (lasko.com): the 9 in. ceramic tabletop heater 754200 (1500 W high, 900 W low), the Ellipse 12 in. ceramic heater CD12950 (Auto Eco mode), and its other heaters' wattage
General guidance from manufacturer and standards data. Products vary, so check the label and the maker's instructions.