A typical dehumidifier uses 300 to 700 watts, which costs roughly $15 to $35 per month to run continuously

The exact amount depends on the dehumidifier's size, how often it runs, and your local electricity rate. A small portable unit drawing 300 watts costs less than a large whole-house model drawing 700 watts. But the biggest factor is runtime: a dehumidifier that runs 8 hours a day uses far less electricity than one running 16 hours.

To find your own cost, check the wattage on the unit's nameplate or manual, multiply by the hours you run it per day, divide by 1,000 to get kilowatt-hours, then multiply by your electricity rate per kilowatt-hour (kWh). Most US rates fall between $0.10 and $0.18 per kWh, though this varies by region and season.

Key Takeaways

  • Dehumidifiers typically draw between 300 and 700 watts depending on size and compressor type, with larger units and rotary screw compressors using more power.
  • A 500-watt dehumidifier running 12 hours daily costs roughly $18 to $32 per month depending on whether your electricity rate is $0.10 or $0.18 per kilowatt-hour.
  • The dehumidifier's runtime matters more than its wattage: a unit that cycles on and off as humidity drops uses less electricity than one running constantly.
  • Energy Star certified dehumidifiers use about 15 percent less electricity than standard models of the same capacity.

Wattage ranges by dehumidifier size and type

Small portable dehumidifiers, typically rated for rooms up to 500 square feet, draw 300 to 400 watts. Mid-size units covering 500 to 1,500 square feet use 400 to 600 watts. Large units and whole-house dehumidifiers can draw 600 to 900 watts or more.

The compressor type also affects power draw. Rotary screw compressors, found in commercial and high-capacity units, use more electricity than reciprocating compressors in standard portable models. Desiccant dehumidifiers (which use absorbent material instead of refrigeration) typically draw 300 to 500 watts but may run longer to reach the same humidity level.

Check your unit's nameplate—usually on the back or bottom—for the exact wattage. If the label shows amperage instead, multiply amps by 120 volts to get watts. A 5-amp unit, for example, draws 600 watts.

How to calculate your monthly electricity cost

Start with three numbers: the dehumidifier's wattage, how many hours per day you run it, and your electricity rate per kilowatt-hour. Your utility bill shows the rate; if it does not, call your provider or check their website.

The formula is: (Watts ÷ 1,000) × Hours per day × Days per month × Rate per kWh = Monthly cost. A 500-watt dehumidifier running 12 hours daily for 30 days at $0.12 per kWh costs (500 ÷ 1,000) × 12 × 30 × $0.12 = $21.60 per month.

If you do not know your exact rate, use the US average of $0.14 per kWh as a rough estimate. Rates in Louisiana and Oklahoma average around $0.10 per kWh, while Massachusetts and Hawaii exceed $0.20 per kWh.

Why runtime matters more than wattage alone

A dehumidifier does not always run at full power. Most units have a humidistat that turns the compressor off once the room reaches your target humidity level, then restarts it when humidity rises again. A unit set to 50 percent humidity in a naturally dry climate might run only 4 hours daily, while the same unit in a damp basement could run 16 hours or more.

This is why two identical 500-watt dehumidifiers can have vastly different monthly costs. One in a dry bedroom might use $8 worth of electricity per month; the same model in a wet crawlspace could use $40. The nameplate wattage tells you the maximum draw, not the average.

To estimate your actual runtime, run the dehumidifier for a few days and note how often the compressor cycles on and off. If it runs roughly half the time, assume 12 hours daily. If it barely cycles, assume 6 hours or less.

Energy Star certified models and efficiency gains

Energy Star certified dehumidifiers use about 15 percent less electricity than non-certified models of the same capacity. A 50-pint Energy Star unit might draw 480 watts instead of 550 watts, saving roughly $3 to $5 per month depending on runtime and your electricity rate.

Over a year, that adds up to $36 to $60 in savings—enough to offset a higher purchase price if the Energy Star model costs $50 to $100 more upfront. The savings are larger in humid climates where the dehumidifier runs year-round.

Look for the Energy Star label on the packaging or product page. The label also lists the unit's integrated energy factor, which measures efficiency across different humidity levels. Higher numbers mean lower electricity use.

Comparing dehumidifier costs to other household appliances

A 500-watt dehumidifier running 12 hours daily uses about 1.8 kilowatt-hours per day. For perspective, a window air conditioner uses 3.5 to 4.5 kWh daily, a clothes dryer uses 3 to 5 kWh per load, and a refrigerator uses 1 to 2 kWh daily. Dehumidifiers fall in the middle of household electricity users—more than a ceiling fan, less than an air conditioner.

If electricity cost is your main concern, reducing runtime is more effective than buying a smaller unit. Running a 500-watt dehumidifier 8 hours daily costs less than running a 350-watt unit 16 hours daily, even though the smaller unit draws less power per hour.

Ways to reduce dehumidifier electricity use

Set the humidistat to 50 to 55 percent relative humidity rather than lower. Each percentage point lower increases runtime and electricity use. Most people feel comfortable in this range, and it prevents mold without overworking the unit.

Place the dehumidifier in the dampest room or area rather than spreading multiple units throughout the house. One large unit in a basement uses less electricity than two small units running in separate rooms. Close doors to unused spaces so the dehumidifier does not waste energy drying areas you do not occupy.

Empty the water bucket or connect a drain hose regularly. A full bucket forces the unit to shut off, and if you forget to empty it, the dehumidifier stops working and humidity rises again. Keeping the bucket empty or using continuous drainage ensures the unit runs only as long as needed.

Clean or replace the filter monthly. A clogged filter makes the compressor work harder and draw more electricity. Most portable dehumidifiers have a washable filter; check your manual for cleaning instructions.

Frequently Asked Questions

Does a dehumidifier use more electricity than an air conditioner?

No. A typical air conditioner uses 3,500 to 4,500 watts and costs $30 to $50 per month to run continuously. A dehumidifier uses 300 to 700 watts and costs $15 to $35 per month. Air conditioners also remove moisture, but they cool the air in the process, which is why they draw more power.

Will running a dehumidifier 24/7 double my electricity bill?

Not necessarily. A dehumidifier running 24/7 costs roughly $30 to $60 per month depending on size and your electricity rate. Most household electricity bills are $80 to $150 per month, so a dehumidifier adds 20 to 40 percent to your bill, not 100 percent. The actual impact depends on your baseline usage and local rates.

Is it cheaper to buy a larger dehumidifier or run a smaller one longer?

Usually cheaper to buy the larger one. A 70-pint unit (700 watts) running 8 hours daily uses less electricity than a 30-pint unit (400 watts) running 16 hours daily. The larger unit removes moisture faster, so it reaches your target humidity sooner and cycles off, while the smaller unit runs longer to catch up.

What does "pint capacity" have to do with electricity use?

Pint capacity measures how much water the dehumidifier removes per day under standard conditions, not how much electricity it uses. A 50-pint unit removes more moisture per hour than a 30-pint unit, so it reaches your target humidity faster and runs less total time. Higher capacity usually means higher wattage, but the faster dehumidification often saves electricity overall.

Can I plug a dehumidifier into a power strip or extension cord?

Check your manual. Most dehumidifiers draw enough current that plugging them into a power strip risks overheating the strip and creating a fire hazard. Plug directly into a wall outlet instead. If you must use an extension cord, use a heavy-duty 12-gauge cord rated for the dehumidifier's amperage, and keep it as short as possible.