How Much Does It Cost to Run a Humidifier per Day and Month?

Source: Planning watts of 40 and 10 hours a day, hours of running time a day in the dry season. Price: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861.

The monthly cost is 1% of the $150.68 average US electric bill. Because it runs only about 5 months a year, the yearly cost is 5 times the monthly figure, not twelve.

One figure cannot fit every home. These three cases show how much the answer moves with the equipment and the hours.

The lowest case costs $2 a month and the highest $13. Use the calculator above to match your own.

The same humidifier costs different amounts depending on the state, because the price per kWh differs. Here are the three cheapest states, the US average and the three costliest, for the same 12 kWh a month.

Source: U.S. Energy Information Administration, Form EIA-861 (final 2025 data). Price is residential revenue divided by sales and includes fixed charges.

See electricity rates in every state to find your own.

A cool mist humidifier uses a small fan or an ultrasonic plate and draws only tens of watts. A warm mist unit heats water to make steam, which takes hundreds of watts. The type of unit is the main thing that sets the cost.

Cool mist units cost little to run. Warm mist units and some large evaporative models use far more. Room size, dryness and the humidity target set how long the unit runs.

The range for this kind of appliance runs from about 20 to 500 watts. At 10 hours a day that is $1 to $26 a month, which is why checking the label on yours is worth the minute.

• Choose a cool mist or evaporative unit if electricity cost matters.
• Set the humidistat around the middle of the comfortable range instead of running it on high.
• Clean the unit as the maker advises, since a dirty filter makes it work harder.

Next step: Dehumidifier costs. For general ideas, read how to lower your electric bill.

Other appliances in the outdoor and extras group: Pool Pump, Hot Tub, Dehumidifier, Aquarium.

The cost is watts divided by 1,000, times hours, times your price per kWh. The 40 watts is a planning figure for this kind of appliance, set from typical product ratings, and the 10 hours is an assumed day of use. Neither is copied from a federal table. Federal guidance describes the method and warns that real wattage varies, so we publish our own typical ranges and label them as such. Prices come from EIA Form EIA-861 for 2025.

The calculation is the standard one used in the U.S. Department of Energy's consumer guidance on estimating appliance energy use. Wattage varies by product age and features, so the label on your own appliance beats any average. Read more in our methodology.