How much does it cost to run a dehumidifier per day?

A typical mid-size dehumidifier running 8 hours a day costs about $0.51 a day at $0.16/kWh; running continuously through a humid season it can cost around $1.50-$1.60 a day.

Is it expensive to run a dehumidifier all day?

Running a mid-size 400W unit 24 hours a day costs roughly $46 a month at US average rates, noticeably more than the $12-$19 typical of an 8-hour daily schedule.

Does dehumidifier size affect the electricity bill much?

Yes; a large 50-70 pint unit typically costs about double a small 20-30 pint unit for the same hours of use, though an undersized unit for a damp space can end up costing more by running near-continuously.

Do Energy Star dehumidifiers really save money?

Yes, typically 10-20% less electricity than a non-certified model of the same capacity, which on a $15 monthly bill saves roughly $1.50-$3 a month.

What humidity setting is cheapest for a dehumidifier?

Setting the target to around 50-55% relative humidity is usually the most cost-effective balance; lowering the target further increases compressor run time and electricity use with diminishing comfort benefit.

Home comfort

Dehumidifier Running Cost Per Day and Per Month

A typical mid-size dehumidifier (30-50 pint capacity) draws 300-500W and costs roughly $0.05-$0.08 per hour at the US average rate of $0.16/kWh, or about $12-$19 a month running 8 hours a day. A larger whole-basement unit can draw 600-700W, costing around $0.10-$0.11 per hour and $24-$27 a month.

Dehumidifiers are a common fixture in basements, humid climates and older homes prone to condensation, and because many households run them for long stretches during humid months, they can add a noticeable amount to a summer electricity bill. Unlike a heater or a kettle, a dehumidifier's actual running cost depends heavily on how humid the space is, since the compressor works harder and runs more continuously when there is more moisture in the air to extract. This guide breaks down typical running costs by unit size and usage pattern.

How dehumidifier wattage scales with capacity

Dehumidifiers are rated by pints of moisture removed per day rather than by a standard wattage class, but capacity and power draw rise together. A small 20-30 pint unit suitable for a single bedroom or small bathroom typically draws 250-350W. A common mid-size 30-50 pint unit for a basement or living area draws 300-500W, and a large 50-70 pint whole-basement unit draws 500-700W. Compressor-based units, the most common type, cycle on and off based on a humidistat setting, similar to a refrigerator, so the wattage rating is the peak draw while running rather than a constant figure; a unit set to a lower target humidity in a genuinely damp space will run closer to continuously than one maintaining a already-dry room.

Cost per hour, day and month

A mid-size 400W dehumidifier running 8 hours a day uses 3.2 kWh, costing about $0.51 a day and roughly $15.36 a month at $0.16/kWh. Run continuously through a very humid basement season, the same unit at 24 hours a day uses 9.6 kWh, costing $1.54 a day and about $46 a month — a level many basement owners see during peak summer humidity before the humidistat starts cycling the compressor off as target humidity is reached. In the UK at 26p/kWh, the same 8-hour daily use costs roughly £25 a month plus the standing charge. Enter your unit's wattage and expected hours into the calculator on the home page for a figure matched to your own climate and basement conditions.

Small unit, 20-30 pint (~300W): about $0.048/hour, $11.52/month at 8 h/day
Mid-size, 30-50 pint (~400W): about $0.064/hour, $15.36/month at 8 h/day
Large, 50-70 pint (~600W): about $0.096/hour, $23.04/month at 8 h/day
Mid-size running continuously in humid season (400W, 24 h/day): about $46/month
Energy Star mid-size unit (~350W, more efficient cycling): about $13/month at 8 h/day

Why real-world cost varies so much between homes

Two identical dehumidifiers can produce very different bills depending on the humidity load in the space. A basement with a persistent water intrusion issue, poor ventilation, or no vapor barrier will see the compressor run almost continuously to hold even a modest target humidity like 50%, while a similarly sized room with good ventilation and no ongoing moisture source may only need the unit to cycle on for a few hours a day once the target is reached. Climate matters too: a Gulf Coast or UK coastal summer with persistently high ambient humidity keeps compressors working far harder than a dry inland climate, where a dehumidifier may only be needed briefly after rain or in an enclosed crawl space.

Energy Star ratings and desiccant vs compressor types

Energy Star-certified compressor dehumidifiers use roughly 10-20% less electricity than non-certified models of the same pint capacity, mainly through more efficient compressors and better humidistat control that avoids unnecessary cycling. Desiccant dehumidifiers, which use a moisture-absorbing wheel and a heating element rather than a compressor, are generally less energy-efficient for whole-room use in warm climates but perform better than compressor units at low temperatures, making them more common in unheated garages or cold basements where a compressor unit's efficiency drops sharply below about 65°F.

Ways to reduce dehumidifier running costs

Set the target humidity to 50-55% rather than a lower setting; each further percentage point down increases compressor run time
Seal obvious sources of moisture, such as a leaking pipe or poor grading around a foundation, rather than relying on the dehumidifier alone
Choose a correctly sized unit for the square footage; an undersized unit runs continuously without ever reaching target humidity
Empty or plumb the drain reservoir so the unit does not shut off and sit idle waiting to be emptied, extending overall run time
Improve ventilation and close off the space being dehumidified from larger, more humid areas of the house

Dehumidifier running cost by size at $0.16/kWh, 8 hours per day

Unit size	Typical watts	Cost per hour	Cost per month	Cost/month (UK 26p)
Small, 20-30 pint	300W	$0.048	$11.52	£18.72
Mid-size, 30-50 pint	400W	$0.064	$15.36	£24.96
Large, 50-70 pint	600W	$0.096	$23.04	£37.44
Mid-size, running 24h/day	400W	$0.064	$46.08	£74.88
Energy Star mid-size	350W	$0.056	$13.44	£21.84

Frequently asked questions

How much does it cost to run a dehumidifier per day?: A typical mid-size dehumidifier running 8 hours a day costs about $0.51 a day at $0.16/kWh; running continuously through a humid season it can cost around $1.50-$1.60 a day.
Is it expensive to run a dehumidifier all day?: Running a mid-size 400W unit 24 hours a day costs roughly $46 a month at US average rates, noticeably more than the $12-$19 typical of an 8-hour daily schedule.
Does dehumidifier size affect the electricity bill much?: Yes; a large 50-70 pint unit typically costs about double a small 20-30 pint unit for the same hours of use, though an undersized unit for a damp space can end up costing more by running near-continuously.
Do Energy Star dehumidifiers really save money?: Yes, typically 10-20% less electricity than a non-certified model of the same capacity, which on a $15 monthly bill saves roughly $1.50-$3 a month.
What humidity setting is cheapest for a dehumidifier?: Setting the target to around 50-55% relative humidity is usually the most cost-effective balance; lowering the target further increases compressor run time and electricity use with diminishing comfort benefit.

Key takeaways

A mid-size dehumidifier costs about $12-$19 a month running 8 hours a day
Running continuously in a very humid season can push cost to $40-$50 a month
Larger 50-70 pint units cost roughly double a small 20-30 pint unit to run
Energy Star models use 10-20% less electricity than non-certified equivalents
A 50-55% humidity target and fixing moisture sources reduce compressor run time the most

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