A dehumidifier uses moderate electricity—typically 300 to 700 watts while running, which costs roughly $10 to $25 per month if you run it continuously
The actual cost depends on three things: the dehumidifier's wattage (printed on the back or in the manual), your local electricity rate, and how many hours per day you run it. A 500-watt dehumidifier running 8 hours daily in a region where electricity costs 14 cents per kilowatt-hour will cost about $5.60 per month. The same unit running 24 hours costs roughly $16.80 per month. Most households run dehumidifiers seasonally or part-time, so the real expense falls somewhere between those numbers.
Dehumidifiers are not among the highest-energy appliances in your home—a window air conditioner or electric water heater uses more. But they do run continuously in many cases, which adds up over weeks or months. The key is understanding your specific unit's power draw and adjusting runtime to match your actual moisture problem.
Key Takeaways
- Most dehumidifiers draw between 300 and 700 watts, which you can find on the product label or in the manual.
- A 500-watt unit running 8 hours daily costs roughly $5 to $7 per month depending on your local electricity rate.
- Dehumidifiers with built-in humidity sensors and auto-shutoff features use less electricity than models that run continuously.
- Running a dehumidifier only in the rooms where you need it, rather than whole-house operation, cuts electricity use significantly.
- Emptying the water tank or using a drain hose keeps the unit running efficiently and prevents it from working harder than necessary.
How to Find Your Dehumidifier's Wattage
The wattage is printed on a label on the back or bottom of the unit, usually in small text near the power cord. It may say "500W" or "500 watts" or appear as part of a longer specification line. If you cannot find it on the unit itself, check the manual—most manufacturers include a specifications page with wattage, voltage, and amperage listed.
If you have the manual but not the wattage, you can calculate it from amperage: multiply the amps listed on the label by the voltage (usually 120 volts in North America). For example, a unit rated at 4.5 amps × 120 volts = 540 watts. Write this number down and keep it with your manual for future reference.
Calculating Your Monthly Electricity Cost
To estimate what your dehumidifier costs to run, you need three numbers: wattage, hours per day, and your electricity rate. Your electricity rate appears on your monthly utility bill, usually listed as cents per kilowatt-hour (kWh). If you cannot find it, call your utility company—they can tell you in one minute.
Use this formula: (Wattage ÷ 1000) × Hours per day × Days per month × Rate per kWh = Monthly cost. For a 500-watt dehumidifier running 8 hours daily at 14 cents per kWh: (500 ÷ 1000) × 8 × 30 × 0.14 = $5.60 per month. If you run it only 4 hours daily, the cost drops to $2.80 per month.
Most people overestimate runtime. If you think you run the dehumidifier 12 hours daily but actually run it 6 hours, your real cost is half what you calculated. Keep a log for a week to get an honest picture of how long the unit actually runs before humidity reaches your target level.
Why Some Dehumidifiers Use Less Electricity Than Others
A 300-watt dehumidifier and a 700-watt dehumidifier remove moisture at different speeds. The smaller unit takes longer to reach your target humidity level, so it may run more hours per day. The larger unit reaches that level faster and can shut off sooner. Over a month, they might use similar total electricity despite different wattages.
Dehumidifiers with a built-in humidistat—a sensor that measures humidity in the room—automatically shut off when humidity drops to your set level. Models without this feature run continuously until you manually turn them off. A humidistat-equipped unit typically uses 30 to 50 percent less electricity than a manual-only model because it does not run unnecessarily.
Larger capacity units (those rated to remove 50 or more pints of water per day) draw more power than smaller ones. If your space is small or your moisture problem is mild, a smaller unit with a humidistat will cost less to operate than an oversized model running constantly.
Common Mistakes That Waste Electricity
Running a dehumidifier in a room with open windows or doors defeats the purpose and wastes electricity. The unit pulls moisture from outside air, which never stops coming in. Close the space first, then run the dehumidifier. This is the single biggest waste of energy with these appliances.
Letting the water tank fill up without emptying it forces the dehumidifier to work harder. Once the tank is full, the unit shuts off automatically on most models, but it has already wasted energy trying to remove water it cannot store. Empty the tank daily or use a drain hose connected to a floor drain or window to let water flow out continuously.
Running the dehumidifier in multiple rooms simultaneously uses far more electricity than treating one room at a time. If you have a moisture problem in a basement and a bedroom, run the dehumidifier in the basement for a week, then move it to the bedroom. This takes longer but costs less than buying a second unit or running one continuously in both spaces.
Comparing Dehumidifier Electricity Use to Other Appliances
| Appliance | Typical Wattage | Monthly Cost (8 hours/day) |
|---|---|---|
| Dehumidifier (500W) | 500 watts | $5.60 |
| Window air conditioner | 1000–1500 watts | $11.20–$16.80 |
| Portable space heater | 750–1500 watts | $8.40–$16.80 |
| Refrigerator (24 hours/day) | 150–800 watts | $6.30–$33.60 |
| Washing machine (per load) | 500–2000 watts | $0.70–$2.80 |
A dehumidifier is less power-hungry than an air conditioner or space heater, but it uses more than most other household appliances when running continuously. The difference is that you run an air conditioner or heater for a season, while a dehumidifier may run year-round in damp climates. Over a full year, the total cost can add up.
The table above assumes 14 cents per kilowatt-hour, which is close to the U.S. average but varies by region. Your actual costs may be higher or lower depending on where you live and your utility's rates.
Ways to Reduce Dehumidifier Electricity Use
Set the humidistat to 50 to 60 percent humidity rather than lower. Every 10 percent drop in target humidity requires the dehumidifier to run longer and work harder. Most people feel comfortable at 50 percent, and mold and dust mites thrive above 60 percent. Setting it to 45 percent uses noticeably more electricity without much benefit.
Place the dehumidifier in the center of the room rather than against a wall or in a corner. Air needs to flow freely around the intake and exhaust vents. A blocked unit works harder and runs longer to achieve the same result. Keep it at least 12 inches away from walls and furniture.
Run the dehumidifier during off-peak hours if your utility company offers time-of-use rates. Some regions charge less for electricity used at night or on weekends. Check your bill or call your utility to see if this option is available. You could save 20 to 30 percent on dehumidifier costs by shifting runtime to cheaper hours.
Seal air leaks in the room—cracks around windows, gaps under doors, and holes where pipes enter. The less outside air enters, the less moisture the dehumidifier has to remove. This is especially important in basements and crawl spaces where outside air naturally seeps in.
Frequently Asked Questions
Is it safe to run a dehumidifier 24 hours a day?
Yes, dehumidifiers are designed to run continuously. However, running one 24 hours daily for a month will cost roughly $16.80 (for a 500-watt unit at 14 cents per kWh). Most people do not need to run them this long. A humidistat-equipped model will shut off automatically when humidity reaches your target, so you do not have to choose between safety and cost.
Does a dehumidifier use more electricity than a fan?
Yes. A typical ceiling or box fan uses 50 to 150 watts, while a dehumidifier uses 300 to 700 watts. A dehumidifier draws 3 to 10 times more power. However, fans and dehumidifiers do different jobs—a fan moves air but does not remove moisture. You cannot replace one with the other.
Will my electric bill go up noticeably if I run a dehumidifier?
It depends on your current usage and local rates. A 500-watt dehumidifier running 8 hours daily adds roughly $5 to $7 per month to a typical household bill. If your bill is currently $120 per month, that is a 4 to 6 percent increase. If you run it 24 hours daily, the increase is roughly 12 to 18 percent.
Can I use a dehumidifier to lower my air conditioning costs?
Not directly. A dehumidifier removes moisture but does not cool air. In humid climates, air conditioning already removes moisture as a side effect of cooling. Running both simultaneously wastes electricity. However, in dry climates where humidity is not a problem, a dehumidifier is unnecessary and adds cost.
What size dehumidifier uses the least electricity?
The smallest unit that can handle your moisture problem uses the least electricity. A 30-pint dehumidifier (rated for small rooms) uses roughly 300 to 400 watts, while a 70-pint unit (for large basements) uses 600 to 800 watts. Buy based on room size and moisture level, not on wattage alone—an oversized unit wastes energy by removing more water than necessary.