A typical dehumidifier uses 300 to 700 watts, which costs roughly $15 to $50 per month to run continuously
The actual cost depends on three things: the wattage of your machine, your local electricity rate, and how many hours per day you run it. A 50-pint dehumidifier (the most common size for basements) usually draws 500 to 700 watts. A smaller 30-pint model draws 300 to 400 watts. If you pay 12 cents per kilowatt-hour — close to the U.S. average — running a 500-watt dehumidifier eight hours daily costs about $12 per month. Running it 24 hours costs roughly $36 per month.
The wattage is printed on the back of the unit or in the manual. Your electricity rate appears on your monthly bill. Multiply wattage by hours of daily use, divide by 1,000, multiply by your rate per kilowatt-hour, then multiply by 30 for a monthly estimate. A 500-watt dehumidifier running 12 hours daily at 12 cents per kilowatt-hour costs about $22 per month.
Key Takeaways
- Most dehumidifiers draw between 300 and 700 watts depending on size and motor type, with larger units consuming more power.
- Monthly cost ranges from $10 to $50 for continuous operation, depending on wattage, local electricity rates, and daily runtime.
- The wattage label is on the back of the unit or in the manual; your electricity rate is on your monthly utility bill.
- Dehumidifiers with a compressor use more power than desiccant models, and running one only when humidity exceeds 60 percent cuts electricity use significantly.
How dehumidifier wattage varies by type and size
Compressor dehumidifiers — the most common type for basements and large rooms — use a refrigeration cycle to cool air and condense moisture. They draw 300 to 700 watts depending on tank size and compressor efficiency. A 30-pint model typically uses 300 to 400 watts. A 50-pint model uses 500 to 700 watts. A 70-pint model can exceed 700 watts.
Desiccant dehumidifiers use a moisture-absorbing material instead of a compressor. They draw 300 to 600 watts but are less efficient in warm, humid conditions. They work better in cold basements and are quieter, but they generate heat as a byproduct, which can raise room temperature slightly.
The wattage printed on the nameplate is the maximum draw under full load. In practice, the compressor cycles on and off as the room humidity drops, so actual consumption is often 30 to 50 percent lower than the rated wattage. A 500-watt dehumidifier may average 200 to 300 watts of actual use over a full day.
What your electricity rate means for monthly cost
Electricity rates vary widely by region and utility company. The national average is around 12 cents per kilowatt-hour, but rates in some states exceed 20 cents, while others fall below 10 cents. Your rate is listed on your monthly utility bill, usually labeled as "rate per kWh" or "energy charge".
To estimate monthly cost, use this formula: (wattage ÷ 1,000) × hours per day × 30 days × your rate per kilowatt-hour. A 500-watt dehumidifier running 10 hours daily in a region with 15-cent electricity costs about $22.50 per month. The same unit in a 10-cent region costs $15 per month.
If you run the dehumidifier only when needed — turning it on when humidity rises above 60 percent and off when it drops below 50 percent — actual runtime may be 6 to 8 hours daily instead of 24, cutting the monthly cost in half.
How runtime affects total electricity use
A dehumidifier's electricity cost scales directly with how long it runs. Running one continuously (24 hours) costs three times as much as running it 8 hours daily. Most homes do not need continuous operation. Basements and bathrooms typically need dehumidification only during humid months or when moisture problems are active.
Using a humidistat — a built-in sensor that turns the dehumidifier on and off automatically — reduces runtime significantly. Most units have a humidistat that maintains a target humidity level (usually 50 to 60 percent). Once the room reaches that level, the compressor shuts off, and the unit consumes almost no power until humidity rises again.
Seasonal use also matters. In dry climates or during winter, you may run the dehumidifier only 2 to 4 months per year. In humid climates, you might run it year-round. A 500-watt dehumidifier used 8 hours daily for 6 months costs roughly $72 annually. Used 24 hours daily for 12 months, it costs roughly $432 annually.
Comparing dehumidifier efficiency and energy use
Energy efficiency ratio (EER) measures how many pints of water a unit removes per kilowatt-hour of electricity. Higher EER means lower cost per pint removed. A 50-pint dehumidifier with an EER of 1.5 removes 1.5 pints per kilowatt-hour. One with an EER of 2.0 removes 2 pints per kilowatt-hour and costs less to operate.
Newer models tend to have higher EER ratings than older ones. A dehumidifier from 2010 might have an EER of 1.2, while a 2023 model of the same size might reach 1.8 or higher. If you replace an old unit, the new one will likely cut electricity use by 20 to 40 percent, offsetting the purchase price within a few years.
Desiccant models are more efficient in cold conditions but less efficient in warm, humid air. Compressor models are more efficient in warm conditions. If your basement stays below 65 degrees, a desiccant unit may use less electricity overall. If it stays above 70 degrees, a compressor model is usually the better choice.
Real-world examples of monthly electricity cost
| Dehumidifier Size | Wattage | Daily Runtime | Monthly Cost (at 12¢/kWh) |
|---|---|---|---|
| 30-pint | 350W | 8 hours | $10 |
| 30-pint | 350W | 24 hours | $30 |
| 50-pint | 550W | 8 hours | $13 |
| 50-pint | 550W | 24 hours | $40 |
| 70-pint | 750W | 8 hours | $18 |
| 70-pint | 750W | 24 hours | $54 |
These figures assume the dehumidifier runs at full rated wattage. In practice, compressor units cycle on and off, so actual consumption is often 30 to 50 percent lower. A 50-pint dehumidifier listed as 550 watts might average 250 to 300 watts over a full day, bringing the actual monthly cost closer to $9 to $11 for 8 hours daily.
The table shows why runtime matters more than wattage alone. A 30-pint unit running 24 hours costs as much as a 50-pint unit running 8 hours. If you need a larger dehumidifier but can limit runtime to 8 to 10 hours daily, the total monthly cost stays reasonable.
Ways to reduce dehumidifier electricity use
Set the humidistat to 55 to 60 percent relative humidity rather than lower. Each percentage point lower requires the dehumidifier to run longer. Maintaining 60 percent humidity uses significantly less electricity than maintaining 45 percent, and 60 percent is still dry enough to prevent mold and dust mites.
Empty the water tank or use a drain hose. A full tank forces the dehumidifier to shut off, but if you forget to empty it, the unit sits idle and wastes the electricity it consumed before stopping. A continuous drain hose eliminates this problem and lets the dehumidifier run unattended.
Place the dehumidifier in a central location and keep doors closed. A dehumidifier works only on the air around it. Placing it in a corner or against a wall reduces airflow. Closing doors to unused rooms concentrates the dehumidification effort and reduces the volume of air the unit must process.
Clean the filter monthly. A clogged filter forces the compressor to work harder and draw more power. A clean filter lets air move freely and reduces strain on the motor.
Frequently Asked Questions
Does a dehumidifier use more electricity than an air conditioner?
A dehumidifier typically uses less power than an air conditioner. A 50-pint dehumidifier draws 500 to 700 watts. A window air conditioner draws 1,000 to 1,500 watts. However, an air conditioner also removes moisture as a side effect, so if you need both cooling and dehumidification, running the AC may cost less than running both units separately.
Will running a dehumidifier increase my electric bill noticeably?
A 50-pint dehumidifier running 8 hours daily adds roughly $12 to $15 per month to your bill. Running it 24 hours adds $35 to $45 per month. For most households, 8 to 12 hours daily is sufficient, making the cost modest. If your bill is already high, the dehumidifier's share is usually 5 to 10 percent of the total.
Is it cheaper to run a dehumidifier or buy a new one?
Running an old, inefficient dehumidifier costs more over time than replacing it with a newer, high-efficiency model. An old unit might cost $50 per month to run, while a new one costs $30. The $20 monthly savings pays for a $300 new dehumidifier in 15 months. If your current unit is more than 10 years old and runs frequently, replacement often saves money within two years.
Can I reduce electricity use by running the dehumidifier only at night?
Running it only at night reduces electricity use proportionally — 12 hours daily costs half as much as 24 hours. However, humidity rises during the day when you are not dehumidifying, which can allow mold to grow. A humidistat that runs the unit as needed, regardless of time of day, is more effective and often uses less total electricity because it stops once the target humidity is reached.
What wattage should I look for when buying a dehumidifier?
Choose based on room size and moisture level, not wattage. A 30-pint dehumidifier (300 to 400 watts) handles small rooms and light moisture. A 50-pint (500 to 700 watts) handles basements and bathrooms. A 70-pint (700+ watts) handles large, very damp spaces. Higher wattage is necessary for larger rooms, not optional. Buying an undersized unit to save electricity will not remove enough moisture and wastes money on a unit that cannot do the job.