Dehumidifier
How much electricity does a dehumidifier use?
300–700 W · continuous operation · $35–$85 per month at 16.5¢/kWh
This is one of the few appliances where the simple watts × hours model works well, because a dehumidifier genuinely runs for hours at a time. A 50-pint unit typically draws 500–600 W and will run continuously until the target humidity is met.
What the label tells you
Dehumidifiers are rated by the energy factor printed on the tag: litres of water removed per kWh. Modern units run about 1.6–2.6 L/kWh. Older units near 1.0 L/kWh remove less water for the same electricity — they run longer and cost more.
Why it feels expensive
A dehumidifier at 500 W for twelve hours a day is 6 kWh daily, 180 kWh a month — roughly $30/month at 16.5¢/kWh, and closer to $80 if you run it around the clock. Compare this to a window AC and you will see they are in the same league, despite the dehumidifier having no compressor starting surge.
The cheapest fix is not a new unit
Sealing the space matters more than efficiency ratings. Running a dehumidifier in a basement with an open stairwell is like air-conditioning a house with the windows open — you are dehumidifying the whole first floor. Close the door, fix the gutter that runs into the wall, and the same unit will cycle off within a few hours instead of running all day.
Frequently asked questions
How many watts does a dehumidifier use?
300–700 W. The figure on the rating label is the maximum draw; actual use varies with settings, age and usage pattern.
How much does it cost to run a dehumidifier per month?
With the defaults above it comes to the monthly figure shown in the calculator. At 16.5¢/kWh — the US residential average — that is a realistic middle estimate. Your own bill may be 30% lower or higher depending on state.
Is it cheaper to run a dehumidifier at night?
Only if your utility offers a time-of-use plan and you avoid the 4pm–9pm peak window. On a flat-rate plan, the time of day makes no difference to the total.
Does the calculator account for real-world duty cycles?
Not automatically — you enter the effective hours yourself. For compressing appliances like refrigerators and AC units, enter the running watts and roughly the proportion of time the compressor is on, which is usually 30–50%.
Will a newer dehumidifier actually save money?
Compare the kWh figure in the calculator against an Energy Star model's stated annual use. If the difference is a few hundred kWh a year, the payback on a replacement is usually long; if it is over 500 kWh, it is worth pricing out.