Dehumidifier Running Cost Calculator: Your Real Rate
What a dehumidifier costs to run per day, month and year, using your own electricity rate rather than a national average.
Running cost is the question people ask after they buy, and national averages are useless for answering it because electricity rates vary so much. This calculator uses the wattage on your own unit and the rate on your own bill.
When this tool helps most
Use it when comparing two units, and when deciding whether to run one continuously or on a humidistat.
How to use this tool
- Find the power draw in watts on the unit label or in the manual.
- Estimate how many hours a day it actually runs, not how many hours it is switched on.
- Enter your electricity rate per kWh from your bill, including per-kWh delivery charges.
- Set how many months of the year you run it.
Worked example
A 480 watt unit running 10 hours a day at 17 cents per kWh costs about $0.82 a day, roughly $24.82 a month while running, and about $173.76 across a seven month season. It uses 4.80 kWh a day.
Understanding your results
The daily figure is the honest one. Run hours fall sharply once the space reaches its target humidity, so a new unit usually costs most in its first few weeks and less thereafter. If your figure looks alarming, the lever is run hours rather than the unit itself.
Common mistakes to avoid
- Using the rated maximum wattage when the unit spends most of its time cycling.
- Forgetting per-kWh delivery charges, which can be a large share of the bill.
- Comparing units on purchase price while ignoring years of running cost.
- Running a dehumidifier to fight a moisture source that could be fixed once.
How to get the most accurate result
- Measure your own basement or crawl space with a tape measure instead of using typical sizes.
- Use the numbers printed on your product labels, manuals and data sheets.
- Change one input at a time to see which assumption matters most.
- Print or save the result and bring it to your installer or contractor.
Next steps
Reduce the hours rather than the rate: seal the space and fix drainage first with the Yard Drainage Grading Calculator.
Frequently asked questions
Far fewer once the space is at target. Expect long hours for the first week or two, then cycling. A unit with a humidistat does this automatically. They remove the same moisture as a similar conventional unit while using less energy, so the saving grows with run hours. Work it out with your own rate. Usually not. Most basements need it through the humid months and far less in winter, when cold air holds little moisture.How many hours a day will it run?
Are ENERGY STAR units worth the premium?
Should I run it all year?
This tool is for planning and education only. It does not store your entries. Structural judgement belongs to a licensed structural engineer, radon mitigation design to a certified mitigator, and mold over roughly 10 square feet to a remediation professional. New circuits are a job for a licensed electrician. Read our disclaimer.