Appliance running costs
Cost to run a dehumidifier
How much does a 500 W dehumidifier cost to run?
A 500 W dehumidifier switched on 24 hours per day at 50% duty cycle uses 6.00 kWh of electricity per day. At $0.180/kWh that is $1.08 per day, about $32.87 per average month and $394.46 per year — 2,191 kWh over the year. Those figures assume a typical wattage and a typical usage pattern; change any input below to match your own appliance and tariff.
Your inputs
Typical example — replace this 500 W default with your appliance’s actual rating for a better estimate.
A thermostat cuts this appliance out once at temperature — typical range around 50%.
No effect at 24 h/day: there are no switched-off hours. Include a continuous idle load in the duty cycle instead.
Use the total variable rate from your bill, including delivery charges per kWh.
$32.87
per month (30.44-day average month)
6.00 kWh per day at 500 W
- Per day
- $1.08
- kWh / month
- 183
- kWh / year
- 2,191
- Per year
- $394.46
Average power across 24 hours
250 W
Daily energy spread evenly over 24 hours. Includes standby draw during switched-off hours when entered.
Cost per running hour
$0.045
While the appliance is actually drawing power.
Effective duty cycle
50%
Share of switched-on time at rated power.
Method
- 500 W = 0.5 kW
- 0.5 kW × 24 h/day × 50% duty = 6 kWh/day active
- 6 kWh × 0.18 USD/kWh = 1.08 USD/day
- 1.08 × 30.436875 days = 32.872 USD/month
- 6 kWh × 365.2425 days = 2191.455 kWh/year
- 2191.455 kWh × 0.18 USD/kWh = 394.462 USD/year
Monthly figures use a 30.44-day average month, 365.24-day average year.
Assumptions
- Electricity rate of 0.18 USD/kWh (editable).
- Calculations use a year of 365.2425 days and an average month of 365.2425 ÷ 12 = 30.436875 days, so twelve average months equal one year exactly. Displayed values are rounded to 365.24 and 30.44 days, and the rounded figures do not multiply out exactly.
- Duty cycle of 50% — the appliance draws rated power for that share of the time it is switched on.
- Rated power is treated as real power in watts, not volt-amps.
What can change the result?
- Room humidity and how much water actually needs removing
- Humidistat setpoint
- Room temperature, since cold rooms trigger defrost cycles
- Unit efficiency in litres or pints removed per kWh
$32.87/mo · 183 kWh/mo
How a dehumidifier actually draws power
A refrigerant dehumidifier runs its compressor until the humidistat setpoint is met, then idles. Duty cycle therefore tracks how damp the space is: a wet basement in humid weather can hold the compressor on almost continuously, while the same unit in a dry room barely runs. Efficiency also falls in cold rooms because the coil frosts and the unit spends time defrosting.
Set the duty cycle from how often you hear the compressor running, not from the humidistat number. Note that essentially all the electricity a dehumidifier uses ends up as heat in the room — that is useful in winter and a cooling load in summer.
Cost at different usage patterns
All rows use 500 W at 50% duty and $0.180/kWh. Only the hours change.
| Hours per day | kWh per day | Per day | Per month | Per year |
|---|---|---|---|---|
| 12 h/day | 3.00 kWh | $0.54 | $16.44 | $197.23 |
| 18 h/day | 4.50 kWh | $0.81 | $24.65 | $295.85 |
| 24 h/day | 6.00 kWh | $1.08 | $32.87 | $394.46 |
Cost across the typical wattage range
Units in this category typically range from 280 W to 800 W. All rows use 24 h/day at 50% duty.
| Power rating | kWh per day | Per day | Per month | Per year |
|---|---|---|---|---|
| 280 W | 3.36 kWh | $0.60 | $18.41 | $220.90 |
| 500 W | 6.00 kWh | $1.08 | $32.87 | $394.46 |
| 800 W | 9.60 kWh | $1.73 | $52.59 | $631.14 |
Worth knowing
Worth knowing
Your next decision
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- Electricity cost calculatorWatts and hours in, cost per day, month and year out.
- Why the rating plate overstates what this appliance usesDuty cycle and part-load operation, which set the figures above.
Your next decision
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Electricity cost tools
- Electricity cost calculatorWatts and hours in, cost per day, month and year out.
- Cost per kWh explainedThree different costs per kWh on one bill, and which one belongs in a calculator.
- Appliance wattage calculatorA configurable appliance list: what this combination draws, and what it costs.
- Watts to run a houseRunning, average and startup watts — separated, not averaged into one range.
Defaults on this page come from the published default registry and the formulas are documented in the methodology.