A typical dehumidifier uses 300 to 700 watts while running, which translates to roughly $10 to $25 per month if it runs eight hours a day
The exact amount depends on three things: the size of the unit (measured in pints per day), how often the compressor cycles on and off, and your local electricity rate. A small 30-pint dehumidifier might draw 300 watts; a large 70-pint model can pull 700 watts or more. Since most dehumidifiers run intermittently—they turn off when the room reaches your target humidity—they do not draw power continuously.
To estimate your own cost, find the wattage on your unit's nameplate (usually on the back or in the manual), multiply by the hours it runs per day, divide by 1,000, then multiply by your utility rate per kilowatt-hour. Your electric bill shows that rate; it typically ranges from $0.10 to $0.20 per kilowatt-hour depending on your region and season.
Key Takeaways
- Most dehumidifiers draw between 300 and 700 watts, but the actual cost depends on how long the unit runs each day, not just its size.
- A dehumidifier that runs eight hours daily costs roughly $10 to $25 per month in most U.S. regions, though this varies by local electricity rates.
- The unit cycles on and off automatically, so it does not consume power at full wattage all day—it only runs when humidity rises above your set point.
- Larger rooms and higher humidity levels force the dehumidifier to run longer, which increases monthly electricity use.
- You can find the exact wattage on the nameplate attached to the unit or in the owner's manual.
How to find your dehumidifier's wattage
The wattage is printed on a label affixed to the back or bottom of the unit. Look for a line that says "Watts" or "W" followed by a number. If you cannot find it on the unit itself, check the owner's manual—most manufacturers list it in the specifications section near the front.
If you have lost the manual, search the model number (also on the nameplate) plus "specifications" or "manual" online. The manufacturer's website usually has a PDF you can read. Knowing the exact wattage is the only reliable way to calculate your actual cost, because two units of the same pint rating can differ by 100 watts or more depending on the compressor and motor design.
Why dehumidifiers cycle on and off instead of running constantly
A dehumidifier has a built-in humidistat—a sensor that measures the moisture in the air. You set a target humidity level (usually between 30 and 60 percent). When the room reaches that level, the compressor shuts off automatically. The unit stays idle until humidity rises again, then the compressor restarts.
This cycling is why a dehumidifier does not consume power at its full rated wattage for 24 hours straight. If a 500-watt unit runs only four hours per day on average, it uses about 2 kilowatt-hours daily, not 12. The longer and more often it cycles, the higher your bill—which is why a dehumidifier in a damp basement runs longer than one in a dry bedroom.
How room size and humidity level affect runtime
A dehumidifier sized too small for the space will run almost constantly, driving up electricity use. A 30-pint unit in a 1,500-square-foot basement may cycle every 15 minutes; the same unit in a 300-square-foot bedroom might run only once or twice a day. The larger the room, the longer it takes to pull moisture out of the air, and the more often the compressor must restart.
Starting humidity also matters. If your basement is soaking wet (80 percent humidity), the dehumidifier will run much longer than if it is merely damp (60 percent). Over time, as you bring the humidity down to your target level, the unit will cycle less frequently and use less electricity. This is why the first week or two of running a dehumidifier often shows higher electric bills than later weeks.
Comparing electricity use across different dehumidifier sizes
| Pint Rating | Typical Wattage | Best Room Size | Estimated Monthly Cost (8 hrs/day) |
|---|---|---|---|
| 30 pints/day | 300–400 watts | Up to 500 sq ft | $7–$10 |
| 50 pints/day | 450–550 watts | 500–1,000 sq ft | $11–$17 |
| 70 pints/day | 600–750 watts | 1,000–1,500 sq ft | $18–$23 |
These estimates assume eight hours of runtime per day and an electricity rate of $0.13 per kilowatt-hour, which is close to the U.S. average. Your actual cost will be higher or lower depending on your local rate and how long the unit runs in your specific space. A dehumidifier in a very damp basement may run 12 hours daily, pushing the monthly cost 50 percent higher; one in a moderately damp room might run only four hours daily, cutting the cost in half.
The table shows why matching the unit size to your room matters. A 70-pint dehumidifier in a small bedroom will cycle constantly and waste electricity, while a 30-pint unit in a large basement will never catch up and will also run excessively. The right-sized unit for your space will have the lowest overall operating cost.
Ways to reduce dehumidifier electricity use
Set your target humidity to 50 or 55 percent instead of lower. Every percentage point you lower the target forces the dehumidifier to run longer. Most people feel comfortable at 45 to 55 percent humidity, so aiming for 50 percent is a reasonable balance between comfort and energy use.
Make sure the unit is sized correctly for the room. An undersized dehumidifier runs constantly and wastes electricity; an oversized one cycles too frequently. Check the manufacturer's recommended room size for your model and match it to your space. If you are treating a very large area, two medium units often use less electricity than one oversized unit, because they can be placed strategically to avoid long air circulation paths.
Keep the intake and exhaust vents clear of dust and obstruction. A clogged filter or blocked vent forces the compressor to work harder and run longer. Clean or replace the filter every two weeks during heavy use. Also, position the unit away from walls and furniture so air can flow freely around it.
Run the dehumidifier during cooler hours if possible. Dehumidifiers work more efficiently in cooler air, so running one at night or early morning may reduce runtime compared to running it during the hottest part of the day. This is a minor effect but worth considering if you have flexibility in your schedule.
When to call a professional about high electricity use
If your dehumidifier is running almost constantly but humidity is not dropping, the unit may have a refrigerant leak, a faulty compressor, or a clogged coil. These problems force the motor to work harder and longer than normal. A technician can diagnose the issue and determine whether repair or replacement makes sense.
If you are unsure whether your dehumidifier is the right size for your space, or if you want to know whether a different model would use less electricity, a local HVAC contractor can assess your room's moisture load and recommend a properly sized unit. This is especially useful in basements or crawl spaces where humidity is chronically high.
Frequently Asked Questions
Will running a dehumidifier all day and night double my electric bill?
Not necessarily. A dehumidifier running 24 hours will use roughly twice as much electricity as one running 12 hours, but most dehumidifiers do not run at full power the entire time—they cycle on and off. If your unit runs eight hours daily on average, running it 16 hours might increase your bill by 50 to 75 percent, not 100 percent, because the compressor will cycle less frequently once humidity is already low.
Is it cheaper to run a dehumidifier or to use air conditioning?
Air conditioning removes moisture as a side effect of cooling, but it uses significantly more electricity than a dehumidifier—typically 3,000 to 5,000 watts compared to 300 to 700 watts. If you need to lower humidity without cooling the space, a dehumidifier is far more efficient. If you are already running air conditioning, you may not need a separate dehumidifier.
Do newer dehumidifiers use less electricity than older ones?
Newer models with inverter compressors or variable-speed motors can be 10 to 20 percent more efficient than older fixed-speed units, but the difference is modest. The biggest factor in electricity use is still the size of the unit and how long it runs. A new, properly sized dehumidifier will always use less electricity than an oversized older model running constantly.
Can I use a power meter to check my dehumidifier's actual electricity use?
Yes. Plug the dehumidifier into a plug-in power meter (available at hardware stores for $15 to $30), and it will display real-time wattage and cumulative kilowatt-hours used. This is the most accurate way to measure your actual cost, because it accounts for the cycling behavior of your specific unit in your specific room.
Does humidity level affect how much electricity a dehumidifier uses?
Yes. The higher the starting humidity, the longer the dehumidifier must run to reach your target level. A basement at 80 percent humidity will require much longer runtime than one at 60 percent. Once you bring the humidity down to your set point, the unit will cycle less frequently and use less electricity going forward.