A typical dehumidifier uses 300 to 700 watts while running, which costs roughly $0.04 to $0.09 per hour to operate
The exact power draw depends on the unit's size, humidity level in your space, and how often the compressor cycles on and off. A small portable dehumidifier (30 pints per day) usually draws 300 to 400 watts. A mid-size unit (50 pints per day) typically uses 500 to 600 watts. Large basement dehumidifiers (70+ pints per day) can reach 700 to 1000 watts. The compressor is the biggest power consumer — it runs intermittently to cool the coils and pull moisture from the air, so your actual usage varies throughout the day.
To estimate your monthly cost, multiply the wattage by the hours you run it per day, divide by 1000, then multiply by your local electricity rate. If you run a 500-watt dehumidifier 8 hours daily at $0.12 per kilowatt-hour, that's roughly $4.80 per month. Running it 24 hours costs about $14.40 monthly. These figures assume the unit runs continuously, but most dehumidifiers cycle on and off as humidity levels change, so real-world costs are often lower.
Key Takeaways
- Small dehumidifiers draw 300 to 400 watts; mid-size units use 500 to 600 watts; large units can exceed 700 watts.
- Operating cost ranges from $0.04 to $0.09 per hour depending on wattage and your local electricity rate.
- The compressor cycles on and off based on humidity, so actual power use is usually lower than continuous-run estimates.
- Monthly costs typically fall between $5 and $20 for average household use, though 24-hour operation can double that.
How to find the wattage of your specific dehumidifier
Check the nameplate on the back or bottom of your unit — it lists the maximum wattage the dehumidifier can draw. Look for "watts" or "W" printed alongside voltage and amperage information. If the nameplate shows amperage instead (for example, 5.5 amps at 120 volts), multiply amps by volts to get watts: 5.5 × 120 = 660 watts.
The manual or product specification sheet also lists wattage. If you have neither, search the manufacturer's website using your model number. Most manufacturers publish full specifications online. The nameplate wattage is the peak draw — the actual average is usually 20 to 40 percent lower because the compressor does not run constantly.
Why dehumidifier power use varies throughout the day
A dehumidifier's compressor turns on when humidity rises above your set point and turns off once the air reaches that target humidity. In a damp basement, the compressor might run almost continuously. In a bedroom with moderate moisture, it may cycle on for 15 minutes, then stay off for an hour. This on-off pattern means your actual power consumption is much lower than the nameplate wattage suggests.
Seasonal changes also affect runtime. In summer, when outdoor humidity is high, the compressor runs longer and more frequently. In winter, especially in heated homes, indoor air is naturally drier, so the dehumidifier runs less often or not at all. A unit that costs $15 per month to run in July might cost only $3 per month in January.
Comparing power use across different dehumidifier sizes
| Dehumidifier Size | Typical Wattage | Estimated Hourly Cost | Estimated Monthly Cost (8 hrs/day) |
|---|---|---|---|
| Small (30 pints/day) | 300–400 W | $0.04–$0.05 | $1.15–$1.53 |
| Mid-size (50 pints/day) | 500–600 W | $0.06–$0.07 | $1.92–$2.30 |
| Large (70+ pints/day) | 700–1000 W | $0.08–$0.12 | $2.88–$4.61 |
These estimates assume an electricity rate of $0.12 per kilowatt-hour, which is close to the U.S. average but varies by region and provider. Your actual costs will be higher or lower depending on your local rate. Check your electricity bill for your rate per kilowatt-hour, then adjust the estimates accordingly.
Ways to reduce dehumidifier energy consumption
Set the humidity target to 50 to 55 percent rather than lower. The lower you set it, the longer the compressor runs. A target of 40 percent forces the unit to work much harder than 55 percent, which is still comfortable and healthy for most homes. Every 5-degree drop in target humidity can increase runtime by 20 to 30 percent.
Position the dehumidifier in the dampest part of the room and keep the intake and exhaust vents clear of obstructions. A unit that has to pull air through blocked vents works harder and uses more power. Close doors to unused rooms so the dehumidifier focuses on the space you actually occupy. Seal obvious air leaks around windows and doors to reduce the amount of outside moisture entering the space.
Run the dehumidifier only during the season when humidity is genuinely high. Many people leave units running year-round out of habit, wasting power in winter when outdoor air is already dry. Use a hygrometer (a straightforward humidity meter, usually $10 to $20) to check actual humidity levels before turning the unit on.
Understanding the difference between nameplate wattage and actual use
The wattage printed on your dehumidifier is the maximum power it can draw under ideal conditions — when the compressor is running at full capacity and the motor is working hardest. In real life, the compressor cycles on and off, so the average power draw is typically 40 to 60 percent of the nameplate figure. A 600-watt dehumidifier might average 250 to 360 watts over a full day.
This is why running-cost estimates based on nameplate wattage alone tend to be too high. If you see a 600-watt dehumidifier and calculate $14.40 per month based on 24-hour continuous operation, the actual cost is probably closer to $6 to $9 per month because the compressor is not running all the time. The longer the humidity stays at your target level, the less the unit runs, and the lower your bill.
Frequently Asked Questions
Does a dehumidifier use more power than an air conditioner?
No. A typical air conditioner uses 3000 to 5000 watts, roughly five to ten times more than a dehumidifier. However, an air conditioner also cools the air, which dehumidifiers do not do. If you need both cooling and dehumidification, running an AC unit is usually more efficient than running both systems separately.
Will running a dehumidifier 24 hours a day significantly increase my electric bill?
It depends on your current usage and local rates. A 500-watt dehumidifier running 24 hours costs roughly $14 to $18 per month in most areas. If your monthly electric bill is $100 to $150, that is a 10 to 15 percent increase. If you are concerned about cost, run it only during high-humidity months or set a higher humidity target.
Can I plug a dehumidifier into a power strip or extension cord?
Most dehumidifier manufacturers recommend plugging directly into a wall outlet because the unit draws significant current and power strips can overheat. Check your manual for the manufacturer's guidance. If you must use an extension cord, use a heavy-duty 12-gauge cord rated for at least 15 amps, and keep it as short as possible.
What size dehumidifier do I need for a 1000 square foot space?
A 50-pint dehumidifier is usually adequate for a 1000 square foot area with moderate moisture. If the space is very damp or poorly ventilated, a 70-pint unit is safer. Larger units use more power but remove moisture faster, so the compressor may actually run less often than an undersized unit that struggles to keep up.