How much does it cost to run an air purifier?
Short answer: An air purifier drawing 50 watts costs about $0.01 per hour at the U.S. average residential price of 18.31¢ per kWh. Used 24 hours a day, 30 days a month, that is about $6.59 per month and $79.10 per year. In Louisiana, the cheapest state, the same use costs $4.58 a month; in Hawaii, the most expensive, $17.28.
Air purifier cost calculator
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Air purifiers are usually left on around the clock. Enter the hours you actually run yours.
Uses 36.0 kWh per month. The starting price is the U.S. residential average; choose your state or type the price from your own bill.
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| Appliance | Usage | Per month | Remove |
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| Per year |
An air purifier is a fan pushing air through a filter. A medium-sized unit draws about 50 watts, but it is normally left running day and night, and that is what makes it add up to several dollars a month.
Cost by size and setting
Costs below use the U.S. average price and 24 hours a day, 30 days a month.
| Type | Power | Per hour | Per month |
|---|---|---|---|
| Small room, low speed | 15 W | 0.3¢ | $1.98 |
| Medium room | 50 W | $0.01 | $6.59 |
| Large room, high speed | 100 W | $0.02 | $13.18 |
Low power, constant use
Fifty watts for 24 hours is 1.2 kWh a day, or 36 kWh a month, about the same as a refrigerator. The wattage depends heavily on fan speed: the same unit might use 10 watts on its lowest setting and 80 on its highest.
What changes the cost
Fan speed, the size of the unit, and how many hours it runs. A model with an automatic mode slows itself down when the air is clean, which cuts its average draw considerably. A clogged filter makes the fan work harder for less airflow.
How to lower the cost
- Use auto mode if the purifier has an air-quality sensor.
- Run it on low overnight and on higher speeds only when needed.
- Replace or clean filters on schedule.
- Choose a unit sized for the room; an oversized one on low is quieter and often more efficient than a small one on high.
How an air purifier compares with other appliances
Typical power and use for each appliance, at the U.S. average price of 18.31¢ per kWh. Follow a link for that appliance's own calculator, or compare two side by side.
| Appliance | Power | Typical use | Energy per month | Cost per month |
|---|---|---|---|---|
| Air purifier | 50 W | 24 hours a day, 30 days a month | 36.0 kWh | $6.59 |
| Humidifier | 40 W | 10 hours a day, 30 days a month | 12.0 kWh | $2.20 |
| Dehumidifier | 500 W | 12 hours a day, 30 days a month | 180.0 kWh | $32.96 |
| Box fan | 75 W | 8 hours a day, 30 days a month | 18.0 kWh | $3.30 |
| Ceiling fan | 50 W | 12 hours a day, 30 days a month | 18.0 kWh | $3.30 |
The math behind the numbers
50 watts ÷ 1,000 = 0.05 kW. 0.05 kW × 24 hours = 1.2 kWh per day. 1.2 kWh × $0.1831 = $0.22 per day. Over 30 days that is 36.0 kWh and $6.59 a month.
Your own figure will differ if your appliance has a different wattage, if you use it more or less, or if your price per kWh is not the national average. Change any of those in the calculator at the top of this page. Our step-by-step guide explains where to find each number.
Cost to run an air purifier in every state
Based on 50 watts for 24 hours a day, 30 days a month, at each state's average residential electricity price for July 2026.
| State | Price per kWh | Per hour | Per month | Per year |
|---|---|---|---|---|
| Alabama | 16.40¢ | $0.01 | $5.90 | $70.85 |
| Alaska | 28.83¢ | $0.01 | $10.38 | $124.55 |
| Arizona | 15.38¢ | $0.01 | $5.54 | $66.44 |
| Arkansas | 14.33¢ | $0.01 | $5.16 | $61.91 |
| California | 33.61¢ | $0.02 | $12.10 | $145.20 |
| Colorado | 17.00¢ | $0.01 | $6.12 | $73.44 |
| Connecticut | 24.16¢ | $0.01 | $8.70 | $104.37 |
| Delaware | 18.48¢ | $0.01 | $6.65 | $79.83 |
| District of Columbia | 25.21¢ | $0.01 | $9.08 | $108.91 |
| Florida | 15.03¢ | $0.01 | $5.41 | $64.93 |
| Georgia | 16.27¢ | $0.01 | $5.86 | $70.29 |
| Hawaii | 48.00¢ | $0.02 | $17.28 | $207.36 |
| Idaho | 13.73¢ | $0.01 | $4.94 | $59.31 |
| Illinois | 19.22¢ | $0.01 | $6.92 | $83.03 |
| Indiana | 16.73¢ | $0.01 | $6.02 | $72.27 |
| Iowa | 15.99¢ | $0.01 | $5.76 | $69.08 |
| Kansas | 15.27¢ | $0.01 | $5.50 | $65.97 |
| Kentucky | 13.81¢ | $0.01 | $4.97 | $59.66 |
| Louisiana | 12.72¢ | $0.01 | $4.58 | $54.95 |
| Maine | 32.41¢ | $0.02 | $11.67 | $140.01 |
| Maryland | 21.41¢ | $0.01 | $7.71 | $92.49 |
| Massachusetts | 30.49¢ | $0.02 | $10.98 | $131.72 |
| Michigan | 23.05¢ | $0.01 | $8.30 | $99.58 |
| Minnesota | 17.45¢ | $0.01 | $6.28 | $75.38 |
| Mississippi | 14.54¢ | $0.01 | $5.23 | $62.81 |
| Missouri | 16.09¢ | $0.01 | $5.79 | $69.51 |
| Montana | 14.99¢ | $0.01 | $5.40 | $64.76 |
| Nebraska | 13.78¢ | $0.01 | $4.96 | $59.53 |
| Nevada | 12.77¢ | $0.01 | $4.60 | $55.17 |
| New Hampshire | 26.60¢ | $0.01 | $9.58 | $114.91 |
| New Jersey | 25.19¢ | $0.01 | $9.07 | $108.82 |
| New Mexico | 16.09¢ | $0.01 | $5.79 | $69.51 |
| New York | 29.90¢ | $0.01 | $10.76 | $129.17 |
| North Carolina | 15.16¢ | $0.01 | $5.46 | $65.49 |
| North Dakota | 13.41¢ | $0.01 | $4.83 | $57.93 |
| Ohio | 19.45¢ | $0.01 | $7.00 | $84.02 |
| Oklahoma | 14.35¢ | $0.01 | $5.17 | $61.99 |
| Oregon | 15.97¢ | $0.01 | $5.75 | $68.99 |
| Pennsylvania | 21.72¢ | $0.01 | $7.82 | $93.83 |
| Rhode Island | 28.29¢ | $0.01 | $10.18 | $122.21 |
| South Carolina | 15.47¢ | $0.01 | $5.57 | $66.83 |
| South Dakota | 15.37¢ | $0.01 | $5.53 | $66.40 |
| Tennessee | 13.71¢ | $0.01 | $4.94 | $59.23 |
| Texas | 15.88¢ | $0.01 | $5.72 | $68.60 |
| Utah | 13.12¢ | $0.01 | $4.72 | $56.68 |
| Vermont | 23.75¢ | $0.01 | $8.55 | $102.60 |
| Virginia | 17.55¢ | $0.01 | $6.32 | $75.82 |
| Washington | 14.71¢ | $0.01 | $5.30 | $63.55 |
| West Virginia | 15.78¢ | $0.01 | $5.68 | $68.17 |
| Wisconsin | 19.06¢ | $0.01 | $6.86 | $82.34 |
| Wyoming | 14.36¢ | $0.01 | $5.17 | $62.04 |
Frequently asked questions
How much does it cost to run an air purifier 24/7?
About $6.59 a month for a 50-watt unit at the U.S. average electricity price.
Do air purifiers use a lot of electricity?
Not much power, but they run constantly. A medium unit uses about as much per month as a refrigerator.
Should I leave my air purifier on all the time?
Most manufacturers recommend continuous use at a low speed, since the air is being filtered only while the unit runs.
Sources
- U.S. Energy Information Administration, Electric Power Monthly (state electricity prices)
- U.S. Department of Energy, Energy Saver: Appliances and Electronics
Electricity prices are the EIA figures for July 2026. Wattages are typical values; check the label on your own appliance.