Dehumidifier Size Calculator

It depends on the floor area and how damp the space feels. The tool starts from a base capacity quoted for 500 square feet, then adds a fixed increment for each additional 500 square feet. Enter your numbers to see the exact pints per day.

It follows 2012 DOE-style guidance. The base for 500 sq ft is 10 pints per day at moderate, 12 at damp, 14 at wet and 16 at very wet, then 4, 5, 6 or 7 more pints per extra 500 sq ft at those same levels. Treat the number as a starting guideline.

The tool takes the base for your dampness level and adds the matching increment times the extra area beyond 500 sq ft, measured in 500 sq ft steps. The result is rounded up to a whole pint and never falls below the base, so a 1,000 sq ft wet space gives 14 plus 6, which is 20 pints per day.

Moderate air feels only slightly humid, damp carries a musty smell, wet shows damp spots or condensation on walls and floors, and very wet has standing moisture or visible seepage. When in doubt, pick the wetter of two options.

The DOE changed its test conditions in 2019 to a cooler, more realistic 65 degrees Fahrenheit, so the same physical machine now lists a smaller pint number. This tool uses the older 2012-style scale that most published sizing charts still follow.

Often yes. Dehumidifiers pull less moisture from cooler air, so in a cold basement a slightly larger unit or a model rated for low temperatures usually performs better than the bare recommendation suggests.

No. Like most published charts it sizes by floor area and dampness only. A room with unusually high ceilings holds more air, so nudging up one size or one dampness level is a sensible adjustment.

The formula keeps scaling, adding the same per 500 sq ft increment however large the area is. For a big open basement you may prefer two units in different corners for even coverage rather than one very large machine.

Yes. The calculation runs entirely in your browser, so the area and dampness you enter never leave your device.