The typical dehumidifier costs $0.50 to $3 per day to run
A small dehumidifier drawing 300 watts costs roughly $0.04 per hour to operate, which works out to about $0.50 to $1 per day depending on how long it runs. A mid-size unit at 700 watts costs $0.08 to $0.10 per hour, or $1.50 to $2.50 daily. Large dehumidifiers using 1,500 watts or more can reach $3 per day. These figures assume an electricity rate of $0.13 per kilowatt-hour, which is close to the U.S. average but varies by region — some areas pay $0.10 per kWh, others $0.18 or higher.
The actual cost depends on three things: the unit's wattage (listed on the nameplate or manual), how many hours per day it runs, and your local electricity rate. A dehumidifier running 8 hours daily will cost roughly one-third as much as one running 24 hours. If you run it only during humid months, your annual cost drops significantly compared to year-round use.
Key Takeaways
- Small dehumidifiers (300 watts) cost about $0.50 to $1 per day; mid-size units (700 watts) cost $1.50 to $2.50 daily; large units (1,500 watts) cost $3 or more per day.
- Monthly cost ranges from roughly $15 to $90 depending on unit size and runtime, assuming average U.S. electricity rates.
- Your actual cost depends on the wattage rating, hours of daily operation, and your local electricity rate, which you can find on your utility bill.
- Running a dehumidifier only during humid seasons rather than year-round can cut annual costs by half or more.
- Energy Star certified dehumidifiers use 15 to 30 percent less electricity than standard models of the same capacity.
How to calculate your dehumidifier's daily cost
Find the wattage on your dehumidifier's nameplate (usually on the back or bottom) or in the manual. Multiply the wattage by the number of hours you run it daily, then divide by 1,000. This gives you kilowatt-hours per day. Multiply that by your electricity rate in cents per kWh (found on your utility bill) and divide by 100 to get the daily cost in dollars.
Example: A 500-watt dehumidifier running 12 hours daily uses 6 kilowatt-hours. At $0.13 per kWh, that costs $0.78 per day, or about $23.40 per month. If you run it only 6 hours daily, the cost drops to $0.39 per day and $11.70 per month.
Many utility websites have online calculators where you enter the wattage and hours; they compute the cost automatically. Your local utility company can also tell you the exact rate you pay, since it may vary by time of day or season.
Monthly and annual costs for common dehumidifier sizes
| Unit Size | Wattage | 8 Hours Daily | 12 Hours Daily | 24 Hours Daily |
|---|---|---|---|---|
| Small (30 pint) | 300–400 W | $10–13/month | $15–20/month | $30–40/month |
| Mid-size (50 pint) | 700–800 W | $22–26/month | $33–39/month | $66–78/month |
| Large (70+ pint) | 1,500+ W | $47+/month | $70+/month | $140+/month |
These estimates assume $0.13 per kilowatt-hour. If your rate is $0.10 per kWh, reduce the figures by about 23 percent. If your rate is $0.16 per kWh, increase them by about 23 percent. Rates in Hawaii, Massachusetts, and California are typically higher; rates in Louisiana, Oklahoma, and Washington are typically lower.
Ways to reduce dehumidifier operating costs
Run the unit only when humidity is above 50 to 60 percent. Many dehumidifiers have a built-in humidistat that turns the unit off automatically when the target humidity is reached, then restarts when humidity rises again. This can cut runtime by 40 to 50 percent compared to running the unit continuously.
Close off unused rooms and run the dehumidifier in the space you actually occupy. A smaller area reaches target humidity faster, so the unit runs fewer hours. Seal air leaks around doors and windows to prevent humid outside air from entering constantly.
Choose an Energy Star certified model if you are buying new. These units remove the same amount of moisture but use 15 to 30 percent less electricity. Over a year or two, the lower operating cost can offset a higher purchase price.
Empty the water bucket or drain it continuously rather than letting it overflow. A full bucket forces the unit to work harder and may shut it off, leaving your space humid. Continuous drainage via a hose to a floor drain or sump pump eliminates this problem.
Seasonal use and annual costs
Most homes need dehumidification only during warm, humid months — typically May through September in northern climates, or year-round in the South and Southeast. Running a mid-size dehumidifier 12 hours daily for 5 months costs roughly $165 to $195 annually. Running it year-round at the same rate costs $400 to $470.
If you live in a dry climate or have good air conditioning, you may need a dehumidifier only in specific rooms or during occasional humid spells. In that case, annual cost could be as low as $30 to $50. Conversely, a basement dehumidifier running year-round in a humid climate can cost $500 to $700 annually.
Dehumidifier efficiency and energy ratings
The Integrated Energy Factor (IEF) measures how many liters of water a dehumidifier removes per kilowatt-hour of electricity used. Higher IEF means lower operating cost. A unit with an IEF of 2.0 removes 2 liters per kWh; one with an IEF of 1.5 removes 1.5 liters per kWh and costs more to run for the same moisture removal.
Energy Star certified dehumidifiers must meet a minimum IEF. When comparing two units of the same capacity, the one with the higher IEF will cost less to operate over time. The IEF is usually listed on the product label or in the specification sheet.
Older dehumidifiers (more than 10 years old) often have lower efficiency ratings and may cost 20 to 40 percent more to run than newer models. If you are running an old unit frequently, replacing it with a modern Energy Star model can reduce your electricity bill noticeably.
Frequently Asked Questions
Does a dehumidifier use more electricity than an air conditioner?
Not usually. A typical air conditioner uses 3,000 to 5,000 watts, while most dehumidifiers use 300 to 1,500 watts. However, an air conditioner cools and dehumidifies at the same time, so if you need both, running the AC is more efficient than running both AC and a separate dehumidifier.
Will running a dehumidifier 24/7 double my electricity bill?
No. A mid-size dehumidifier running constantly adds roughly $60 to $80 per month to your bill, not hundreds of dollars. However, most dehumidifiers have a humidistat and cycle on and off, so they do not actually run 24/7 unless humidity is very high.
Is it cheaper to run a dehumidifier or open windows?
Opening windows is free but only works if outside air is drier than inside air. On humid days, opening windows makes indoor humidity worse. A dehumidifier costs money but works regardless of outdoor conditions and maintains your target humidity consistently.
How much does it cost to run a small portable dehumidifier?
A small 30-pint dehumidifier using 300 to 400 watts costs roughly $10 to $13 per month if run 8 hours daily, or $30 to $40 per month if run 24 hours daily. Actual cost depends on your electricity rate and how often the unit cycles on and off.
Do dehumidifiers use less power when the humidity is already low?
Yes. Once humidity reaches your target level, the humidistat shuts the unit off. It restarts only when humidity rises again. This cycling means the unit does not draw power continuously, so your actual monthly cost is usually lower than the maximum possible cost.