How much does it cost to run a dehumidifier?
Work out what any appliance costs to run per use, per month and per year on your own electricity rate — including what it draws on standby.
Using the Finnish average of 22.54c/kWh — Eurostat, the second half of 2025.
A compressor dehumidifier running eight hours a day. It earns its keep in two separate ways, and only one of them shows up as a saving on this page.
Common cases
What drives the cost
A dehumidifier is unusual on this page because its running cost is the less interesting half of the story. At around 250 W for eight hours a day it is a real but moderate cost — comparable to a television left on far too long. What it is doing for that money is pulling litres of water out of the air, which is what stops windows streaming and corners going black.
The other half is that almost all of the electricity it uses comes back as heat in the room, so in winter very little of it is truly spent — you are dehumidifying and mildly heating at the same time. That makes it much better value than the meter reading suggests, and it is the reason it keeps being recommended over simply opening a window in cold weather, where you would be throwing away heat you paid for. If you are running one to dry washing, the clothes drying calculator prices that job directly and compares it against a tumble dryer.
How this is worked out
Electricity is billed per kilowatt hour. An appliance's kilowatt hours are its power in kilowatts multiplied by the hours it runs — so a 2,000 W appliance running for 30 minutes uses 1 kWh. Multiply that by your unit rate and you have the cost. The standing charge is not included here because you pay it whether or not you switch anything on.
What this assumes
- The appliance draws its rated power for the whole time it is on. Anything thermostatically controlled — ovens, heaters, fridges — cycles on and off, so the real figure is lower.
- Your unit rate stays flat all day. On a time-of-use tariff the same appliance costs materially different amounts depending on when you run it.
- A year is 52 weeks of identical use, which overstates seasonal appliances and understates ones you use in bursts.
- The rate filled in for you is an average that spreads fixed charges across a year's usage, so it sits above what one extra unit really costs. Entering the unit rate from your own bill gives a closer answer.
Questions
Is a dehumidifier expensive to run?
Moderate, and cheaper in practice than the figure suggests. The headline is a few hundred watts while the compressor runs, but it cycles rather than running flat out, and nearly all the energy it uses ends up as heat in the room. In winter that offsets your heating; in summer it is a genuine cost.
Is a dehumidifier cheaper than opening a window?
In winter, usually yes, which surprises people. Opening a window removes moisture but also removes the heat you paid for, and cold outdoor air has to be warmed once it is inside. A dehumidifier removes the water while keeping the heat in the room. In mild weather, ventilation is free and wins easily.
Does this include the standing charge?
No, and deliberately. The standing charge is a fixed daily fee for being connected at all, so it does not change when you run an appliance more or less. Including it would make every appliance look more expensive than it is.
Where do I find the wattage?
On the rating plate — usually a sticker on the back, base or inside the door — or in the manual. It is written as W or kW. If it only quotes amps, multiply amps by 230 to get watts.
Why is my bill higher than the total this gives?
Because this prices one appliance. Heating, hot water and the constant background draw of everything left plugged in usually make up more of a bill than the appliances people think to check.
Sources
- Ofgem — price cap unit rates — checked 2026-08-21
- Energy Saving Trust — quick tips to save energy — checked 2026-08-21
Rates from Eurostat for the second half of 2025. Last reviewed 3 September 2026.