Dehumidifier Size Calculator
Find the right dehumidifier capacity for a damp room or basement. Enter the floor area and how damp the space feels to see the recommended pints per day.
How to size a dehumidifier
- Enter the floor area of the space in square feet.
- Pick how damp it feels: moderate, damp, wet or very wet.
- Read the recommended capacity in pints removed per day.
- Choose a unit rated at or above that pint capacity.
Examples
500 sq ft, moderate dampness
500 sq ft, moderate
10 pints per day
1,500 sq ft, moderate dampness
1,500 sq ft, moderate
18 pints per day
Frequently asked questions
What size dehumidifier do I need?
It depends on the area and how damp the space is. This tool starts from a base capacity for 500 square feet, then adds more for each extra 500 square feet.
What sizing rule does this use?
It follows 2012 DOE-style guidance. The base for 500 sq ft is 10 pints/day moderate, 12 damp, 14 wet and 16 very wet, plus 4, 5, 6 or 7 pints for each additional 500 sq ft. These are guidelines.
How do I judge the dampness level?
Moderate feels slightly humid, damp has a musty smell, wet shows damp spots on walls or floors, and very wet has standing moisture or seepage.
Why are newer pint ratings lower?
Test conditions changed in 2019, so the same dehumidifier now lists a lower pint number. This tool uses the older 2012-style scale that many sizing charts still follow.
Should I size up for a cold basement?
Often yes. Dehumidifiers remove less moisture in cooler air, so a slightly larger unit or a model rated for low temperatures can help in a cold basement.
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