How much does it cost to run an under-desk heater?
An under-desk heater costs about 2.6¢ per hour, 15¢ a day, $4.52 a month and $23 a year at typical use (8 hours a day, 5 days a week for 5 months a year) and the U.S. average rate of 17.99¢/kWh. Radiant panel and foot warmer heaters draw 30-300 W and warm only your legs and feet, which is why they cost a fraction of a 1,500 W space heater.
Calculate your cost
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Cost by setting
| Setting | Watts | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|---|
| Heated foot warmer | 50 | 0.8¢ | 4.4¢ | $1.33 | $7 |
| Radiant panel | 170 | 2.6¢ | 15¢ | $4.52 | $23 |
| Large panel | 300 | 4.6¢ | 26¢ | $7.98 | $40 |
At 8 hours a day, 5 days a week for 5 months a year and 17.99¢/kWh.
Cost by hours of use
| Hours per day | kWh/day | Per day | Per month | Per year (all year) |
|---|---|---|---|---|
| 1 hour | 0.10 | 1.9¢ | $0.57 | $7 |
| 2 hours | 0.21 | 3.7¢ | $1.13 | $14 |
| 4 hours | 0.41 | 7.4¢ | $2.26 | $27 |
| 8 hours | 0.83 | 15¢ | $4.52 | $54 |
| 12 hours | 1.24 | 22¢ | $6.78 | $81 |
| 24 hours | 2.48 | 45¢ | $13.56 | $163 |
Cost to run an under-desk heater in every state
The same under-desk heater costs $15 a year in North Dakota and $55 in Hawaii, at each state's average residential rate (12 months ending July 2026).
| State | Rate | Per hour | Per month | Per year |
|---|---|---|---|---|
| North Dakota | 12.32¢ | 1.8¢ | $3.10 | $15 |
| Idaho | 12.65¢ | 1.8¢ | $3.18 | $16 |
| Nebraska | 12.86¢ | 1.9¢ | $3.23 | $16 |
| Louisiana | 12.99¢ | 1.9¢ | $3.26 | $16 |
| Utah | 13.32¢ | 1.9¢ | $3.35 | $17 |
| Nevada | 13.36¢ | 1.9¢ | $3.36 | $17 |
| Arkansas | 13.43¢ | 1.9¢ | $3.38 | $17 |
| Tennessee | 13.56¢ | 2.0¢ | $3.41 | $17 |
| Oklahoma | 13.70¢ | 2.0¢ | $3.44 | $17 |
| Montana | 13.84¢ | 2.0¢ | $3.48 | $17 |
| Kentucky | 13.92¢ | 2.0¢ | $3.50 | $17 |
| Missouri | 13.95¢ | 2.0¢ | $3.51 | $18 |
| Wyoming | 14.01¢ | 2.0¢ | $3.52 | $18 |
| Washington | 14.12¢ | 2.0¢ | $3.55 | $18 |
| Iowa | 14.13¢ | 2.0¢ | $3.55 | $18 |
| South Dakota | 14.20¢ | 2.1¢ | $3.57 | $18 |
| Mississippi | 14.77¢ | 2.1¢ | $3.71 | $19 |
| North Carolina | 14.77¢ | 2.1¢ | $3.71 | $19 |
| Kansas | 15.09¢ | 2.2¢ | $3.79 | $19 |
| Georgia | 15.12¢ | 2.2¢ | $3.80 | $19 |
| New Mexico | 15.32¢ | 2.2¢ | $3.85 | $19 |
| Florida | 15.39¢ | 2.2¢ | $3.87 | $19 |
| Arizona | 15.40¢ | 2.2¢ | $3.87 | $19 |
| West Virginia | 15.48¢ | 2.2¢ | $3.89 | $19 |
| Oregon | 15.50¢ | 2.2¢ | $3.90 | $19 |
| South Carolina | 15.64¢ | 2.3¢ | $3.93 | $20 |
| Texas | 15.96¢ | 2.3¢ | $4.01 | $20 |
| Minnesota | 16.22¢ | 2.3¢ | $4.08 | $20 |
| Alabama | 16.44¢ | 2.4¢ | $4.13 | $21 |
| Virginia | 16.48¢ | 2.4¢ | $4.14 | $21 |
| Colorado | 16.58¢ | 2.4¢ | $4.17 | $21 |
| Indiana | 16.94¢ | 2.4¢ | $4.26 | $21 |
| Delaware | 17.79¢ | 2.6¢ | $4.47 | $22 |
| Ohio | 18.25¢ | 2.6¢ | $4.59 | $23 |
| Wisconsin | 18.74¢ | 2.7¢ | $4.71 | $24 |
| Illinois | 18.79¢ | 2.7¢ | $4.72 | $24 |
| Pennsylvania | 20.70¢ | 3.0¢ | $5.20 | $26 |
| Maryland | 21.03¢ | 3.0¢ | $5.29 | $26 |
| Michigan | 21.05¢ | 3.0¢ | $5.29 | $26 |
| New Jersey | 23.78¢ | 3.4¢ | $5.98 | $30 |
| Vermont | 23.80¢ | 3.4¢ | $5.98 | $30 |
| District of Columbia | 24.20¢ | 3.5¢ | $6.08 | $30 |
| New Hampshire | 26.67¢ | 3.9¢ | $6.70 | $34 |
| Alaska | 26.85¢ | 3.9¢ | $6.75 | $34 |
| Connecticut | 27.99¢ | 4.0¢ | $7.03 | $35 |
| New York | 28.39¢ | 4.1¢ | $7.14 | $36 |
| Rhode Island | 29.27¢ | 4.2¢ | $7.36 | $37 |
| Maine | 29.31¢ | 4.2¢ | $7.37 | $37 |
| Massachusetts | 30.43¢ | 4.4¢ | $7.65 | $38 |
| California | 32.99¢ | 4.8¢ | $8.29 | $41 |
| Hawaii | 43.51¢ | 6.3¢ | $10.94 | $55 |
How to cut the cost
- Use it with the office or home thermostat set 4-6°F lower; that is where the real savings come from.
- Put it on a smart plug or outlet timer set to your work hours so it never runs overnight or weekends.
- Drape a blanket over your lap and the panel to trap the heat; this lets you use the low setting.
- Choose a model with an automatic shutoff after 4-8 hours.
Cheaper ways to get the job done
Covers more of your body at a similar 50-100 W.
See options on AmazonEnsures the heater only runs during working hours.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Compare with similar appliances
| Appliance | Watts | Typical use | Per month | Per year |
|---|---|---|---|---|
| Under-desk heater | 170 | 8 hours a day, 5 days a week for 5 months a year | $4.52 | $23 |
| Small space heater | 400 | 6 hours a day for 5 months a year | $9.25 | $46 |
| Heated throw | 100 | 3 hours a day for 5 months a year | $1.04 | $5 |
| Space heater | 1,500 | 6 hours a day for 5 months a year | $29.67 | $148 |
| Heating pad | 50 | 1 hour a day | $0.19 | $2 |
| Heated mattress pad | 150 | 8 hours a day for 5 months a year | $3.00 | $15 |
| Snow melting mat | 200 | 8 hours a day, 2 days a week for 4 months a year | $2.50 | $10 |
Head-to-head comparisons
Frequently asked questions
How much does it cost to run an under-desk heater per hour?
An under-desk heater drawing 170 watts uses 0.14 kWh per hour while running (85% duty cycle). At the U.S. average of 17.99¢/kWh that's 2.6¢ per hour. In North Dakota (12.32¢) it's 1.8¢. In Hawaii (43.51¢) it's 6.3¢.
How much does it cost to run an under-desk heater per month?
At typical use (8 hours a day, 5 days a week for 5 months a year), an under-desk heater costs about $4.52 a month while in use and $23 a year over the 5 months it's typically used, at the U.S. average rate. Enter your ZIP in the calculator above for your utility's rate.
How many watts does an under-desk heater use?
Most under-desk heaters use 30 to 300 watts, depending on the setting (heated foot warmer 50 W, radiant panel 170 W, large panel 300 W). Check the label on the back or bottom for your model's exact rating.
How many kWh does an under-desk heater use?
About 0.83 kWh a day and 126 kWh a year at typical use (8 hours a day, 5 days a week for 5 months a year).
Does an under-desk heater use a lot of electricity?
No. At about 126 kWh a year it's a small share (1.2%) of the average U.S. home's 10,492 kWh.
Is it cheaper to run an under-desk heater or a small space heater?
At typical use, an under-desk heater costs about $23 a year versus $46 for a small space heater. So the under-desk heater is cheaper by about $24 a year. Use the comparison table above to compare them at your own settings.
How can I lower the cost of running an under-desk heater?
- Use it with the office or home thermostat set 4-6°F lower; that is where the real savings come from.
- Put it on a smart plug or outlet timer set to your work hours so it never runs overnight or weekends.
- Drape a blanket over your lap and the panel to trap the heat; this lets you use the low setting.
Rates updated 2026-10-21: EIA data through July 2026. Typical wattage and usage reviewed against DOE, ENERGY STAR and manufacturer specs. Methodology.