Enter your dehumidifier's watts, measured kWh, or yearly kWh to estimate its monthly electricity cost and energy use.
Advanced options
Added usage-based electricity cost. Fixed utility, purchase, and maintenance charges are not included.
Meter and annual-energy figures already include cycling, so active time is not applied again.
Power and meter projections use the active-month setting.
A short meter sample may not represent other seasons or humidity levels.
Actual daily use can change with humidity, temperature, room leakage, and the humidity setting.
Table of contents
How to use our Dehumidifier Electricity Cost Calculator
- Choose the option under "Energy information you have" that matches the number you can copy: a watt rating, a plug-in meter reading, or annual energy use.
- Enter "Electricity rate (cents per kWh)" from your utility bill. Include usage-based supply and delivery charges if listed separately, but leave out fixed monthly customer or meter charges.
- For "Power draw in watts," enter "Power draw (watts)," "Scheduled use (hours per day)," and "Days used in the month."
- For "Measured kWh over several days," enter the accumulated "Measured energy use (kWh)," its "Measurement period (days)," and the projected "Days used in the month."
- For "Annual energy use," enter "Annual energy use (kWh per year)." The calculator uses one-twelfth for the monthly average and one 365th for the daily average.
- For the watts method, open "Advanced options" and adjust "Active time during scheduled hours (percent)" only if the unit cycles on and off. Leave it at 100 for a full-power estimate.
- For watts or meter projections, change "Active months per year" if this month's pattern happens only during part of the year. Then select "Calculate."
- Read "Estimated monthly dehumidifier electricity cost" first. Check the monthly kWh beside it to see how much electricity creates that cost.
Definitions
Watt (W): A unit of electrical power. It tells how fast an appliance uses electricity while it is running.
Kilowatt-hour (kWh): A unit of electrical energy used on utility bills. A 1,000-watt appliance running for one hour uses 1 kWh.
Usage-based electricity rate: The part of an electric bill charged per kWh. It can include supply and delivery charges that change with use, but not fixed customer or meter charges.
Active time: The share of scheduled hours when the dehumidifier draws its entered running power. A humidistat, which turns the unit on and off to control humidity, can cause cycling.
Active months per year: The number of months when the selected monthly pattern is expected to occur. It affects annual projections from watts or measured kWh.
Common mistakes and quick fixes
Mistake: Entering a water-removal rating, such as pints per day, as "Power draw (watts)."
Fix: Find electrical input power on the nameplate, manual, specification sheet, or a plug-in power meter. Pints per day measures moisture removal, not electricity use.
Mistake: Typing a dollar amount into "Electricity rate (cents per kWh)."
Fix: Enter cents. For a rate of 18.31 cents per kWh, enter 18.31, not 0.1831.
Mistake: Applying the active-time percentage to measured kWh or annual kWh.
Fix: Do not reduce those figures for cycling. A meter total and an annual kWh figure already reflect the appliance's energy use over their stated periods.
Mistake: Treating a short meter reading as typical for the whole year.
Fix: Measure during normal conditions when possible. If the dehumidifier mainly runs in humid months, use a lower "Active months per year" value for the annual projection.
Limitations & Key Assumptions / Boundary Conditions
- This estimates added usage-based electricity cost. It excludes fixed customer charges, meter charges, the appliance price, and maintenance costs.
- The watts method assumes the entered power is the running electrical input and that the schedule and active-time percentage describe typical operation.
- Humidity, room temperature, air leaks, the humidity setting, and appliance condition can change actual energy use.
- A meter reading is projected to the entered use days and active months. A short reading or unusual weather period may not reflect other months.
- An annual kWh figure is treated as a full-year total, so active time and active months do not change that method.
- The starting electricity rate is a planning estimate. Replace it with the usage-based rate from your own bill.
Methodology
Energy calculation
The calculator uses one energy source at a time. The watts method uses a schedule, the meter method divides observed kWh by its measurement days, and the annual method divides yearly kWh by 365 for a daily average.
daily kWh = (watts / 1000) x hours per day x (active time percent / 100)
This formula applies only to "Power draw in watts."
daily kWh = measured kWh / measurement days
This formula applies only to "Measured kWh over several days."
daily kWh = annual kWh / 365
This formula applies only to "Annual energy use."
monthly kWh = daily kWh x days used in the month
For annual-energy mode, monthly kWh is the entered annual kWh divided by 12 instead.
annual kWh = monthly kWh x active months per year
This annual projection applies to the watts and meter methods. Annual-energy mode uses the entered annual kWh directly.
Cost calculation
cost in dollars = kWh x electricity rate in cents per kWh / 100
Monthly, daily, and annual costs use matching unrounded energy values. Dividing by 100 converts the entered cents rate to dollars.
Worked example
A 500-watt dehumidifier scheduled for 8 hours per day over 30 days at 100 percent active time uses 120 kWh for the month.
(500 / 1000) x 8 x 30 x (100 / 100) = 120 kWh
At 18.31 cents per kWh, the monthly usage-based cost is $21.97 after rounding.
120 x 18.31 / 100 = 21.972 dollars
The starting rate of 18.31 cents per kWh is the July 2026 U.S. residential average from the U.S. Energy Information Administration and is a planning default. [1]