Hub / Running cost
488 watts, twelve hours a day, $32 a month
Almost nobody publishes a dehumidifier's power draw. The inputs are public, in a US government dataset, and the arithmetic is three lines long. Here is the number, the formula, and a calculator that shows both.
Go straight to the calculator if you know your unit's size, or read watts by size if you do not.
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The short answer
A 50-pint dehumidifier draws about 488 watts while running. Twelve hours a day at the US average residential rate of 18.34 cents per kWh costs $1.07 a day, $32.24 a month, or $392 a year. A 30-pint unit at 318 W costs about $21 a month on the same schedule.
The problem this hub exists to solve
Try to find out what a dehumidifier draws. Retail listings state pints and square feet. Manufacturer pages state dimensions and warranty terms. Of the 21 units in our registry, exactly one prints a wattage on its listing. The running-cost question that every buyer asks has, for most machines, no published input at all.
The calculators that have filled that gap are worse than nothing. The most-cited one in the category is offline pending re-verification. The main working alternative ships a 46 W default for a dehumidifier - roughly a tenth of what a real 50-pint unit draws - and it does not show you that default, so you cannot see that it is wrong.
Where our numbers come from
The ENERGY STAR program publishes its full certified product list as open data. Every certified dehumidifier row carries two things we need: the model's water removal capacity in pints per day at the DOE test condition, and its Integrated Energy Factor in liters of water removed per kilowatt-hour. Those two numbers give you the power draw directly:
A median certified 50-pint unit
(488 W / 1000) x 12 h x $0.1834/kWh = $1.07 per day
0.488
kWh per hour
$32.69
per month, 12 h/day
$65.38
per month, 24 h/day
Rate is the US residential average of 18.34 cents/kWh from the EIA Electric Power Monthly, June 2026. Yours will differ - use the calculator.
We ran that across all 527 certified portable models, from 136 brands, on 2026-09-01. The cross-check is the part that matters: dividing each model's published annual energy consumption by the wattage we computed gives an implied annual run time, and across the whole list the median is 1,074 hours with the middle half between 1,055 and 1,091. A spread that tight across 136 unrelated manufacturers means the derivation agrees with a figure ENERGY STAR publishes independently. The full wattage table.
What that means per month
| DOE class | Median watts | 8 h/day | 12 h/day | 24 h/day |
|---|---|---|---|---|
| ~10 pint | 105 W | $4.62 | $6.93 | $13.87 |
| 20-22 pint | 258 W | $11.36 | $17.04 | $34.08 |
| 30-32 pint | 318 W | $14.00 | $21.00 | $42.01 |
| 35 pint | 351 W | $15.45 | $23.18 | $46.37 |
| 50 pint | 488 W | $21.48 | $32.24 | $64.47 |
Computed as (watts / 1000) x hours x 30.44 days x $0.1834. Rate is the EIA US residential average for June 2026. Your own rate is almost certainly different - Hawaii is 52.72 cents and Nevada is 13.11 - so use the calculator.
The number that actually decides it
Watts are only half the story. A machine that is too small for the room never cycles off, so it runs at its full draw all day and still loses. A correctly sized machine reaches the target humidity and idles. Undersizing to save 170 W can cost more than the 170 W would have.
That is why sizing and running cost are the same conversation, and why the calculator asks for hours per day rather than assuming them. Twelve hours is a reasonable summer figure for a correctly sized basement unit on a humidistat. Twenty-four is what an undersized one does.
FAQ
Questions
How much electricity does a dehumidifier use per day?
Is it cheaper to run a dehumidifier all the time or in bursts?
Do dehumidifiers use more electricity than air conditioners?
Sources
Sources
We have not tested these products. How we work explains what we do instead, and how this site is funded.