How Much Does It Cost to Run a Dehumidifier?
About $28.10 a month for a 50-pint dehumidifier running 12 hours a day, at the 2024 average rate of $0.16/kWh — 176 kWh, or 0.078 dollars an hour. That month of running pulls about 93 gallons of water out of the air, which works out at $0.30 a gallon. Set your own wattage, hours and rate below.
Size
Average draw while the compressor runs. Nameplate peak reads a little higher.
Hours the compressor runs, not hours switched on. On a humidistat the two are not the same.
Dehumidifier cost per month
$28.11
176 kWh at $0.16/kWh — $341.99 a year if it runs like this all year, or $0.08 an hour.
Water removed
93 gal
353 litres a month at 2.01 L/kWh
Cost per gallon removed
$0.30
The only fair way to compare two units
Energy per day
5.9 kWh
12 h of running at 488 W
0.488 kW × 12 h × 30 days = 176 kWh × $0.16 = $28.11. Switch to the 20-pintand the hourly cost falls — but so does the water, and the cost per gallon goes up.
Don't know the hours? Use the bucket
Removing 10 pints of water a day takes a 50-pint about 4.8 hours of compressor time, costing $11.30 a month. The bucket is a meter: it tells you what the machine actually did, which the switch on the front does not.
Capacity and efficiency are the certified values for real ENERGY STAR units of each size, rated in DOE's 65°F test chamber. IEF (Integrated Energy Factor, litres per kWh) is the federal efficiency metric and includes standby energy, so the water figures here are, if anything, a shade conservative. Costs assume a 30-day month and cover electricity only. Running for part of the year costs part of the annual figure. Set the humidistat no lower than 50% and it will run fewer hours than any of this assumes. Not sure of your rate? Check average rates by state.
How much electricity does a dehumidifier use?
Monthly cost = watts ÷ 1,000 × hours the compressor runs × days × price per kWh
The wattage is easy and the rate is easy. The hours are where every estimate goes wrong, because a dehumidifier on a humidistat does not run for the hours you switched it on — it runs until the room reaches the target humidity, then cycles off. Leave one on for 24 hours in a dry room and the compressor may run for two of them.
Worked example (50-pint at 488 W, 12 hours a day, $0.16/kWh): 0.488 kW × 12 h = 5.9kWh a day × 30 days = 176kWh × $0.16 = $28.10 per month.
Monthly cost by running hours and electricity rate
Columns are hours of compressor time a day. Rows are common US electricity rates. All figures are for a 50-pint unit drawing 488 W while it runs.
| Rate ($/kWh) | 4 h/day | 8 h/day | 12 h/dayTypical | 16 h/day | 24 h/day |
|---|---|---|---|---|---|
| $0.10 | $5.85 | $11.71 | $17.56 | $23.42 | $35.13 |
| $0.13 | $7.61 | $15.22 | $22.83 | $30.44 | $45.67 |
| $0.16 (US avg) | $9.37 | $18.73 | $28.10 | $37.47 | $56.20 |
| $0.22 | $12.88 | $25.76 | $38.64 | $51.52 | $77.28 |
| $0.33 | $19.32 | $38.64 | $57.96 | $77.28 | $115.92 |
A 30-day month, electricity only. Most dehumidifiers run for part of the year rather than all of it, so multiply by the months you actually run yours. Find your own rate on the rates by state page.
Why your bill beats the number on the box
The 50-pint above is certified at 525 kWh a year. Divide that by the 488 W it draws while running and you get about 1076 hours of running a year — under three hours a day. A basement unit at 12 hours a day runs 4,380 hours and uses about 2137 kWh, roughly 4.1 times the certified figure. That number is a fair way to rank two models against each other. It was never a forecast of your bill.
It is also a space heater
Essentially all the electricity a dehumidifier draws ends up as heat in the room, and condensing the water releases more. ENERGY STAR puts it plainly: a dehumidifier warms the space around it. In a basement that is a bonus. In a room you are cooling, your window AC now pays to remove that heat — and it was already wringing water out of the air on its own, because that is what cooling a coil below the dew point does. Two machines, one job, two bills.
Watts on the nameplate, watts on the meter
The 488W used here is the average draw while the compressor runs, derived from the unit's certified capacity and efficiency. Nameplate ratings quote peak draw and read higher — our dehumidifier appliance page uses a 600 W nameplate, which at the same 12 hours a day gives $34.56 a month. If you have measured your own unit with a plug-in meter, use that figure in the calculator above.
Dehumidifier running cost by size: 30-pint vs 50-pint vs 70-pint
Those are the three sizes people shop for, and only one of them still means what it did a few years ago. Capacity is quoted in pints of water a day. Efficiency is quoted as Integrated Energy Factor — litres of water removed per kWh — and it is the number that decides the bill, because a dehumidifier is paid by the water it removes, not by the hour. Every figure below is the certified value for a real ENERGY STAR unit of that size.
| Size | Rated capacity | Efficiency (IEF) | Draw while running | Cost per month (12 h/day) | Water removed | Cost per gallon |
|---|---|---|---|---|---|---|
| 20-pintA bedroom, a closet or a small bath | 22.31pints/day | 1.70L/kWh | 259 W | $14.90 | 42 gal | $0.36 |
| 35-pintA damp room or a dry-ish basement | 35.32pints/day | 2.01L/kWh | 346 W | $19.96 | 66 gal | $0.30 |
| 50-pintA wet basement -- the largest portable size sold | 49.74pints/day | 2.01L/kWh | 488 W | $28.10 | 93 gal | $0.30 |
Capacity and IEF as certified by ENERGY STAR, rated in DOE's 65°F test chamber. Draw while running is derived from those two figures and sits inside the band of published nameplate ratings for each size. Water removed and cost per month both assume 12 hours of compressor time a day at $0.16/kWh.
Read the last column, not the fifth
The 20-pint looks like the cheap one: $14.90 a month against $28.10. It is cheap the way a smaller shovel is cheap. In that month it lifts 42 gallons of water out of the air against the 50-pint's 93, and each of those gallons costs $0.36 rather than $0.30. Federal minimum efficiency rises with capacity — from 1.30 to 1.60 litres per kWh — and certified products follow, so the bigger machine is the more efficient one per litre.
Give the 20-pint the 50-pint's actual workload — 353 litres a month — and it needs $33.23 of electricity, about 18% more, spread over 803 hours of running. A 30-day month only contains 720. The undersized unit does not just cost more per gallon; in a genuinely wet basement it never catches up at all.
Where the 70-pint dehumidifier went
Two things happened. First the ruler changed: since 2019 DOE rates portable dehumidifiers in a 65°F chamber rather than the old 80°F one, chosen because it looks more like a basement. Cooler air holds less moisture, so the identical machine removes fewer pints a day under the new test and wears a smaller number on the box. There is no official conversion between the two ratings and the published estimates disagree with each other, so a pint figure from before 2019 simply cannot be compared with one from after it.
Then the rules changed. The minimum efficiency a portable unit must meet steps up sharply at the top of the range:
| Capacity class | Federal minimum IEF | ENERGY STAR IEF |
|---|---|---|
| 25.00 pints/day or less | 1.30 L/kWh | 1.70 L/kWh |
| 25.01 to 50.00 pints/day | 1.60 L/kWh | 2.01 L/kWh |
| 50.01 pints/day or more | 2.80 L/kWh | 3.30 L/kWh |
Cross 50.01 pints a day and the requirement leaps from 1.60 to 2.80litres per kWh. On the certified list, the units sold as “50-pint” are rated 49.74 to 49.95 pints a day — every one of them tucked just under the line. Today the 50-pint class is the big one, and it is the largest portable size you will find.
So what about the 30-pint?
A 30-pint unit sits in the same 25.01 to 50.00 pints/day class as the 35-pint above, so it faces the same 1.60 L/kWh federal floor and the same 2.01 L/kWh for ENERGY STAR. Its efficiency per litre is therefore much the same; it simply removes less water per hour and draws proportionally fewer watts while doing it. Size the machine to how wet the space actually is. The only sizing mistake that costs real money is going too small, because then it runs constantly and still loses.
Tips to reduce dehumidifier energy use
Every kWh a dehumidifier burns is spent moving water. So there are only two ways to spend less: give it less water to move, or move each litre more efficiently. Everything below is one or the other.
Set it to 50%, not as low as it goes
ENERGY STAR puts the healthy indoor range at 30–50% relative humidity. 50% is the one to aim at. Every point below it is more water pulled from the air and more compressor hours to pull it, for no comfort and no less mould.
Fix where the water comes from
This is the big one, because litres are the bill. Clear gutters, slope soil away from the foundation, seal the rim joist, cover a crawlspace floor, and keep basement windows shut on humid days. Water that never gets in never has to be condensed back out at $0.30 a gallon.
Buy the bigger one, within reason
Larger units are held to a higher efficiency standard and remove each litre for less — $0.30 a gallon against $0.36 for the 20-pint. Wildly oversizing has its own penalty, though: a unit that satisfies the humidistat in minutes short-cycles, and a short-cycling compressor falls short of its rated efficiency.
Choose ENERGY STAR — it is 20% off, forever
Certified models use about 20% less energy than non-certified ones. That is roughly $5.62 a month on the 50-pint above, in every month it runs. Our Energy Star guide covers when the premium pays back.
Give it air, and keep the coils clean
ENERGY STAR asks for clearance around the cabinet so air circulates freely, doors and windows closed, and the unit kept away from dust that clogs the coils and grills. A choked coil moves less air, condenses less water per kWh, and quietly undoes the efficiency you paid for.
Mind a cold basement
Below about 65°F, frost forms on the coils and the compressor cycles on and off without removing much water — paying for hours that do nothing. If the space runs cold, buy a unit specified for low temperatures rather than turning a standard one up.
Do not dehumidify a cooled room
An air conditioner already condenses water out of the air as it cools. Adding a dehumidifier to the same room does the job twice and dumps its own waste heat back into the space, which the AC then pays again to remove.
Let the heat work for you in winter
The flip side: in a heating season, the heat a dehumidifier sheds is heat your furnace or space heater does not have to make. It is a poor way to buy heat, but if the machine has to run anyway, that heat is not wasted. More ideas in our energy savings guide.
Related Guides
Cost to Run a Window AC
The machine already pulling water out of your air
Cost to Run a Space Heater
What a dehumidifier quietly doubles as in winter
How to Save on Energy Bills
Practical tips by room with savings
Electricity Rates by State
Find your state's average rate
Dehumidifier Cost Calculator
Quick watts-and-hours estimate on the main tool
Energy Star Guide
Is upgrading worth the cost?
Frequently Asked Questions
How much does it cost to run a dehumidifier?
About $28.10 a month to run a 50-pint dehumidifier for 12 hours a day at the 2024 US average rate of $0.16/kWh — roughly 0.078 dollars an hour, or 176 kWh a month. Three things set that number: the wattage while the compressor runs, the hours it actually runs, and your electricity rate. The hours are the slippery one, because a humidistat decides them, not you.
How much electricity does a dehumidifier use?
A 50-pint unit draws about 488 watts while its compressor is running, so 12 hours a day is 5.9 kWh a day and 176 kWh a month. A 20-pint unit draws about 259 watts. But watts alone are misleading: the machine's job is measured in water, and the federal efficiency metric, Integrated Energy Factor, is quoted in litres of water removed per kWh.
Is it cheaper to run a small dehumidifier?
By the hour, yes. For the work done, no. A 20-pint costs $14.90 a month against the 50-pint's $28.10 — but it removes only 42 gallons of water in that month against 93. Per gallon removed it costs $0.36 against $0.30, because federal minimum efficiency rises with capacity and certified products follow. To pull the same 353 litres out of the air, the small unit would burn $33.23 of electricity and need 803 hours of running — in a month that only contains 720. It cannot keep up, and it charges more per gallon for falling behind.
Why can't I buy a 70-pint dehumidifier any more?
Because the ruler changed, and then the rules did. Since 2019 the Department of Energy has rated portable dehumidifiers in a 65°F test chamber instead of the old 80°F one. Cooler air holds less moisture, so the very same machine removes fewer pints a day under the new test and carries a smaller number on the box. On top of that, the efficiency a unit must meet jumps from 1.60 to 2.80 litres per kWh the moment its rating passes 50.01 pints a day. Certified "50-pint" units are rated 49.74 to 49.95 pints a day — just under the line. There is no official conversion between old and new ratings, and published estimates disagree, so never compare a pint number from before 2019 with one from after it.
Why is my bill higher than the dehumidifier's annual kWh rating?
Because that rating assumes the machine barely runs. The 50-pint's certified figure of 525 kWh a year works out to about 1076 hours of running — under three hours a day. A basement unit at 12 hours a day runs 4,380 hours and uses roughly 2137 kWh, about 4.1 times the sticker. The certified number is fine for comparing two models against each other. It is not a forecast of your bill.
Does a dehumidifier heat up the room?
Yes. Essentially all the electricity it draws leaves as heat, and condensing water vapour releases heat of its own, so a dehumidifier warms the space it dries — ENERGY STAR says as much. In a basement that is usually welcome. In a room you are air conditioning it is not, because the air conditioner then pays to remove the heat the dehumidifier just added. An air conditioner already dehumidifies as a side effect of cooling, so running both in the same room is often doing one job twice.
Is an ENERGY STAR dehumidifier worth it?
ENERGY STAR certified dehumidifiers use about 20% less energy than non-certified models. Because a dehumidifier's cost is proportional to the water it removes divided by its efficiency, that discount applies to every litre for the life of the machine. On the 50-pint above, at $28.10 a month, 20% is about $5.62 a month back in every month it runs.
What humidity should I set a dehumidifier to?
ENERGY STAR puts the comfortable, mould-resistant indoor range at 30–50% relative humidity. 50% is the setting to reach for, because every point below it is more water pulled out of the air and more compressor hours to pull it. Drying a basement to 30% costs real money and buys nothing. If the space is routinely below 65°F, look for a unit rated for low temperatures — frost forms on the coils below that and the compressor cycles without removing much water.