How Much Electricity Does a Dehumidifier Use?

Cost depends on the unit's wattage and how often it actually runs. A small unit draws roughly 300–350 W and a large one roughly 500–600 W. At 500 W running half the time, that is about 6 kWh a day, or around $0.90 a day at $0.15/kWh.

• kWh per day = watts / 1,000 x hours running.
• Cost = kWh x your price per kWh.
• Use duty cycle, not 24 hours: a unit with a humidistat cycles on and off.
• Example: 500 W x 12 effective hours = 6 kWh; at $0.15/kWh that is $0.90 per day, about $27 per month.

• How damp the space is: a wet basement makes the unit run almost continuously.
• Temperature: compressor units work harder and defrost more in cold air.
• Your setpoint: a lower target humidity means more running time.
• Unit efficiency: ENERGY STAR models use less energy for the same water removal.
• Size: an oversized unit may short-cycle; an undersized one runs nonstop.

A plug-in energy monitor gives the real number in your home. Plug the dehumidifier into the monitor for a few days and read the accumulated kWh; multiply by your electricity price. This is more accurate than the label, which only shows the maximum draw.

• Set a realistic target humidity (often around 45–50%) instead of running continuously.
• Use continuous drainage so a full tank does not stop it and waste cycles.
• Seal the space and fix leaks so you are not dehumidifying the outdoors.
• Choose an ENERGY STAR unit when replacing an old one.
• Run it during off-peak hours if your tariff has them.

ENERGY STAR dehumidifier efficiency criteria; U.S. Department of Energy guidance on estimating appliance electricity use.