A 20-pint portable dehumidifier draws about 205 W and costs $27.27 a month if the compressor runs 24 hours a day, at the U.S. average of 18.19¢/kWh — $6.82–$20.45 with a humidistat cycling it.
At 18.19¢/kWh — U.S. average, Jan–Aug 2026 (EIA).
| Period | kWh | Cost |
|---|---|---|
| Per hour plugged in | 0.205 | $0.04 |
| Per day | 4.93 | $0.90 |
| Per month | 149.9 | $27.27 |
| Per 12-month year | 1,799 | $327 |
| 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% | 4.9 | $0.90 | $27.27 | $327 |
| 75% | 3.7 | $0.67 | $20.45 | $245 |
| 50% | 2.5 | $0.45 | $13.64 | $164 |
| 25% | 1.2 | $0.22 | $6.82 | $81.82 |
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.