A 50-pint portable dehumidifier (pre-2019 rating) draws about 308 W and costs $40.91 a month if the compressor runs 24 hours a day, at the U.S. average of 18.19¢/kWh — $10.23–$30.68 with a humidistat cycling it.
At 18.19¢/kWh — U.S. average, Jan–Aug 2026 (EIA).
| Period | kWh | Cost |
|---|---|---|
| Per hour plugged in | 0.308 | $0.06 |
| Per day | 7.39 | $1.34 |
| Per month | 224.9 | $40.91 |
| Per 12-month year | 2,699 | $491 |
| Capacity | Watts | Per month |
|---|---|---|
| 20 pints | 205 | $27.27 |
| 30 pints | 308 | $40.91 |
| 35 pints | 342 | $45.36 |
| 50 pints | 488 | $64.80 |
| Compressor on | kWh a day | Per day | Per month | Per year |
|---|---|---|---|---|
| 100% | 7.4 | $1.34 | $40.91 | $491 |
| 75% | 5.5 | $1.01 | $30.68 | $368 |
| 50% | 3.7 | $0.67 | $20.45 | $245 |
| 25% | 1.8 | $0.34 | $10.23 | $123 |
IEF (Integrated Energy Factor) is liters of water removed per kWh on the DOE test, so watts at rated capacity = liters per day ÷ IEF ÷ 24. With a humidistat the compressor stops once the air is dry enough, so real use depends on how damp the space is.
Prices: EIA U.S. average for Jan–Aug 2026. Efficiency: ENERGY STAR certified averages and 10 CFR 430.32 minimums.
The full method, material data and tips are on the main dehumidifier cost calculator page.