Dehumidifier running-cost calculator
Work out how much it costs to run a dehumidifier, from its power rating, usage and your electricity price.
Result
Cost per year
Cost per week
How to use this calculator
- Check your dehumidifier's power rating — most domestic units are 200–450W.
- Enter how many hours a day and days a week you run it.
- Enter your electricity price per kWh.
- Read the estimated cost per week and per year.
Assumptions
- Assumes the unit runs at full rated power the whole time it's on — many dehumidifiers cycle off once the target humidity is reached, so real usage is often lower.
Technical details: what the fields mean
- Dehumidifier power
powerWatts - Power rating from the unit's label — most domestic dehumidifiers are 200–450W.
- Hours per day
hoursPerUse - How many hours a day it actually runs.
- Days per week
daysPerWeek - How many days a week you use it.
- Electricity price
pricePerKwh - Your electricity price per kWh.
Methodology
Energy per week = power (kW) × hours per day × days per week. Cost = energy × price per kWh, projected to a year.
Worked example
300W unit, 6 hours/day, 7 days/week, 27p/kWh
Inputs: powerWatts=300, hoursPerUse=6, daysPerWeek=7, pricePerKwh=0.27
Result: £3.40/week, £176.80/year
Practical guidance
- A humidistat setting (running until a target humidity is reached, then stopping) cuts real running time well below 'hours switched on'.
- Running a dehumidifier in a smaller, sealed room is more efficient than a large or draughty one.
Common mistakes
- Assuming the unit runs continuously at full power for the whole time it's switched on, when most cycle off once the target humidity is reached.
FAQs
How much does it cost to run a dehumidifier?
At 300W, 6 hours a day and 27p/kWh, about £3.40 a week if run every day.