Dehumidifier size calculator
How big a dehumidifier do you need? ENERGY STAR sizes them by how damp the space is and how big it is, in pints of water removed per day. Ratings changed in 2019, so older advice quotes bigger pint numbers.
Dehumidifier size chart
| Condition | Up to 2,000 sq ft | Over 2,000 sq ft |
|---|---|---|
| Slightly to moderately damp 50-75% RH | 20-30 pints | 30+ pints |
| Very damp 75-90% RH | 25-40 pints | 40+ pints |
| Wet 90-100% RH | 30-50 pints | 50+ pints |
ENERGY STAR. When in doubt, ENERGY STAR says it's better to go a size up than down.
Old vs new pint ratings
ENERGY STAR approximate equivalence (old = through 2019, new = 2020+). DOE test changed portable test temp from 80°F to 65°F; new standards effective June 2019. Varies by model.
| Type | Old rating | About the same as |
|---|---|---|
| portable | 30 pints | 20 pints |
| portable | 40 pints | 25 pints |
| portable | 50 pints | 30 pints |
| portable | 55 pints | 30-35 pints |
| portable | 60 pints | 35 pints |
| portable | 70 pints | 40-45 pints |
| portable | 90 pints | 55 pints |
| whole-home | 80 pints | 70 pints |
| whole-home | 100 pints | 85 pints |
| whole-home | 120 pints | 100 pints |
| whole-home | 140 pints | 115 pints |
| whole-home | 160 pints | 135 pints |
| whole-home | 200 pints | 170 pints |
What humidity to aim for
EPA: keep below 60% RH, ideally 30-50%. ENERGY STAR: optimum 30-50%; 30-40% in cold climates during heating season to prevent window condensation.
Running cost: see how many watts a dehumidifier uses and the full sizing guide.