A typical dehumidifier uses 300 to 700 watts while running, which costs roughly 25 cents to $1.50 per day depending on your local electricity rate and how long it runs

The actual daily cost depends on three things: the wattage of your machine, how many hours it runs, and what your utility company charges per kilowatt-hour (kWh). A 50-pint dehumidifier—the most common size for basements—usually draws 500 to 700 watts. A smaller 30-pint model might use 300 to 400 watts. If your electricity costs $0.12 per kWh (close to the U.S. average, though rates vary by region), running a 500-watt dehumidifier for 8 hours costs about 48 cents that day.

The machine does not run constantly at full power. Most dehumidifiers have a humidistat—a built-in sensor that turns the unit off once the room reaches your target humidity level, then turns it back on when humidity rises again. In a damp basement, it might run 12 to 16 hours a day. In a moderately humid space, it might cycle on and off for only 4 to 6 hours total. This cycling is why two identical machines in different rooms can have very different monthly bills.

Key Takeaways

  • A 50-pint dehumidifier typically uses 500 to 700 watts and costs between 50 cents and $1.50 per day, depending on runtime and your local electricity rate.
  • The humidistat inside the machine turns it off when humidity drops, so actual daily use varies widely—a unit might run 4 hours one day and 14 hours the next.
  • Smaller 30-pint models use 300 to 400 watts and cost less per day, but may not keep up in very damp spaces.
  • You can estimate your own cost by multiplying the wattage by hours run per day, dividing by 1,000, and multiplying by your utility rate per kWh.

How to find your dehumidifier's wattage

Check the label on the back or bottom of the unit, or look at the manual. The wattage is usually listed as "watts" or "W" and often appears near the electrical specifications. If you cannot find it, the model number on the label will let you search the manufacturer's website for the spec sheet.

Do not confuse wattage with amperage (amps). A dehumidifier that draws 5 amps on a 120-volt outlet uses 600 watts (5 × 120 = 600). If you only have the amp rating, multiply it by 120 to get watts.

Calculating your daily electricity cost

Use this formula: (Wattage ÷ 1,000) × Hours run per day × Your rate per kWh = Daily cost.

Example: A 600-watt dehumidifier running 10 hours per day in an area where electricity costs $0.13 per kWh would cost (600 ÷ 1,000) × 10 × $0.13 = $0.78 per day, or about $23 per month.

To find your electricity rate, check your utility bill. It is usually listed as "rate per kWh" or "energy charge" and varies by region, season, and time of day in some areas. If you live in a state with deregulated electricity (like Texas or Pennsylvania), your rate depends on your chosen supplier.

Why runtime varies so much day to day

A dehumidifier does not run at the same hours every day because humidity levels change. On a rainy day when outdoor moisture seeps in, the unit might run 14 hours. On a dry day, it might run only 3 hours before reaching your target humidity and shutting off.

Seasonal changes also matter. In summer, especially in humid climates, dehumidifiers run longer. In winter, when cold air holds less moisture, they run less—or not at all if you live somewhere dry. A basement dehumidifier in the Midwest might run 12 hours daily in July but only 2 hours in January.

The size of the space and how well it is sealed also affect runtime. A sealed, insulated basement loses moisture more slowly than an open, drafty one, so the dehumidifier cycles off sooner and uses less power.

Smaller versus larger dehumidifiers and their power use

A 30-pint dehumidifier (for spaces up to 1,500 square feet) typically uses 300 to 400 watts. A 50-pint model (for 2,000 to 3,000 square feet) uses 500 to 700 watts. A 70-pint industrial-sized unit can draw 1,000 watts or more.

Choosing the right size matters for cost. An undersized dehumidifier will run constantly and use more power overall because it cannot keep up with the moisture load. An oversized one will cycle off quickly and use less. For most basements and crawl spaces, a 50-pint model is the practical middle ground—large enough to handle typical dampness without running all day.

Ways to reduce dehumidifier electricity use

Set your humidistat to 50 to 55 percent relative humidity rather than lower. Each percentage point lower means the unit runs longer. Most people feel comfortable and mold growth slows at 50 percent, so going lower wastes power without much benefit.

Keep the intake and exhaust vents clear of dust and blockages. A clogged filter forces the motor to work harder and use more power. Clean or replace the filter every month during heavy use.

Place the dehumidifier in a central location where air can circulate freely around it. Tucking it in a corner or against a wall reduces airflow and makes it work longer to pull moisture from the whole room.

Seal obvious sources of moisture if you can. Fixing a foundation crack, improving drainage around the house, or venting a clothes dryer outside reduces the overall moisture load, so the dehumidifier does not have to run as long.

Comparing dehumidifier costs to other household appliances

A dehumidifier uses less power than most people expect. A window air conditioner uses 1,000 to 1,500 watts. A space heater uses 750 to 1,500 watts. A hair dryer uses 1,200 to 1,800 watts. So a 500-watt dehumidifier running 10 hours a day actually costs less than running a space heater for 4 hours.

Over a month, a dehumidifier might add $15 to $40 to your electric bill, depending on size and climate. That is usually worth the cost if it prevents mold, musty odors, or moisture damage to stored items.

Frequently Asked Questions

Does a dehumidifier use more electricity if the room is very wet?

Yes. A very damp basement forces the dehumidifier to run longer before the humidistat shuts it off. In extremely wet conditions, it might run 16 to 20 hours per day instead of 8 to 10, doubling or tripling your daily cost. This is temporary—as the space dries out, runtime drops.

Will turning off the dehumidifier at night save money?

It will save money that night, but humidity will rise while it is off, and the unit will run longer the next day to catch up. For most people, letting the humidistat do its job (turning the unit on and off automatically) uses less total power than manual on-off switching.

Does the type of dehumidifier affect power use?

Yes. Refrigerant dehumidifiers (the most common type) use less power in warm, humid conditions. Desiccant dehumidifiers use more power but work better in cold basements. For the same capacity, a refrigerant model typically costs less to run.

What if my dehumidifier runs all the time and never shuts off?

The humidistat may be broken, or your target humidity is set too low. Check that the setting is at least 50 percent. If the unit still runs constantly, the humidistat sensor may need cleaning or replacement. A constantly running unit will significantly increase your electricity bill and should be serviced.

Can I use a dehumidifier and air conditioner together without a huge electric bill?

Yes. An air conditioner already removes some moisture as it cools, so a dehumidifier will run less often when both are in use. In summer, they often work well together without dramatically raising your bill—the AC does most of the cooling and some dehumidifying, and the dehumidifier handles the rest.