Show the formula and working
This dehumidifier running cost calculator works out what a compressor or desiccant dehumidifier costs to run per hour, per day, per week and per year, for households in the UK, Ireland and the rest of Europe dealing with damp, condensation or drying laundry indoors. Enter the wattage, the hours it runs and your unit rate to see the kWh used and the cost in pounds or euros.
Quick answer: A dehumidifier running cost calculator multiplies the power in kW by the hours it runs and your price per kWh. A 200 W compressor dehumidifier uses 0.2 kWh an hour, so at 26.32p per kWh it costs about 5.3p an hour, or 42.1p for 8 hours. A 650 W desiccant model costs about 17.1p an hour.
What Is a Dehumidifier Running Cost Calculator?
A dehumidifier running cost calculator is a tool that converts a dehumidifier’s wattage and daily use into kilowatt hours and then into money. In plain words: divide the watts by 1,000 to get kilowatts, multiply by the hours it runs at full power, then multiply by your electricity unit rate.
The formula is cost = watts x hours / 1,000 x price per kWh. Most dehumidifiers have a humidistat that pauses the compressor or heater once the room reaches the target humidity, so the calculator lets you set how much of the time it really runs. If you add the litres of water it collects in a day, it also shows the cost of every litre removed, which is a handy way to compare two machines.
How Do You Use the Dehumidifier Running Cost Calculator?
- Enter the Dehumidifier power in watts from the rating label or manual. Use the figure for the mode you run, such as laundry or low fan.
- Enter the Hours used per day.
- Set Time it runs at full power. Keep 100% for continuous or laundry mode, or lower it if the humidistat often pauses the machine.
- Enter the Days used per week and Weeks used per year.
- Optionally enter the Water collected per day in litres to see the cost per litre.
- Check the Electricity unit rate against your bill, and switch to euros if you pay in cents.
- Read the cost per day, per hour and per year, then open “Show the formula and working” to check each step.
How Much Does a Dehumidifier Cost to Run per Hour?
Most home compressor dehumidifiers cost about 4p to 7p per hour, because they draw roughly 150 to 250 W and electricity costs 26.32p per kWh under the Ofgem price cap for October to December 2026. Desiccant models draw more, often 300 to 700 W, so they cost about 8p to 18p per hour. Your model’s label gives the exact figure.
| Example power | Typical type | Cost per hour | Cost for 8 hours | Cost per year (8 h daily) |
|---|---|---|---|---|
| 150 W | Compressor, low energy 10 to 12 L | 3.9p | 31.6p | £114.97 |
| 200 W | Compressor, 12 to 20 L | 5.3p | 42.1p | £153.29 |
| 250 W | Compressor, larger | 6.6p | 52.6p | £191.62 |
| 350 W | Desiccant, low setting | 9.2p | 73.7p | £268.26 |
| 650 W | Desiccant, high setting | 17.1p | £1.37 | £498.18 |
Costs use 26.32p per kWh, 7 days a week for 52 weeks, with the machine running all the time it is on. The wattages are examples, not figures for a particular model.
Is a Compressor or Desiccant Dehumidifier Cheaper to Run?
A compressor dehumidifier is usually cheaper to run in a heated home at around 20 °C, because it draws less than half the power of a typical desiccant model for a similar amount of water. The Wikipedia dehumidifier article notes that refrigerant units work best in warmer air and lose effectiveness in the cold, while desiccant units suit high humidity at low temperatures.
That makes a desiccant model a reasonable choice for an unheated garage, conservatory or boat in winter. A desiccant dehumidifier also releases most of the energy it uses as warmth into the room, which can help drying laundry. For a living room or bedroom that is already heated, a compressor model normally removes more water per kWh.
Is It Cheaper to Dry Clothes With a Dehumidifier?
Drying a load with a 200 W dehumidifier for 6 hours uses 1.2 kWh, about 31.6p at 26.32p per kWh, which is usually less than a vented or condenser tumble dryer uses per load. Put the airer in a small room with the door shut and the dehumidifier close by, and the clothes dry faster and the machine runs for fewer hours. You can check other appliances with the electricity cost calculator.
Should You Run a Dehumidifier All Day?
You rarely need to run a dehumidifier all day: set the humidistat to about 50% to 60% relative humidity and let it pause once that is reached. Running it continuously at 200 W for 24 hours costs about £1.26 a day. Damp that keeps coming back usually points to a leak, poor ventilation or a cold wall, which a dehumidifier will not fix on its own.
Worked Example: A Bedroom Dehumidifier
Example: a 200 W compressor dehumidifier in a bedroom with condensation runs 8 hours a day, every day of the year, with Time it runs at full power left at 100%, and leaves 4 L in the tank each morning. The unit rate is 26.32p per kWh.
- Energy per day: 0.2 kW x 8 hours = 1.6 kWh
- Cost per day: 1.6 kWh x 26.32p = 42.1p
- Cost per week: 11.2 kWh x 26.32p = £2.95
- Cost per year (364 days): 582.4 kWh x 26.32p = £153.29
- Cost per litre removed: 42.1p / 4 L = 10.5p
A household in the Netherlands runs the same machine the same way and pays an example rate of 35c per kWh, so the daily cost is 1.6 kWh x 35c = 56c. More tools for household bills are in the energy bill calculators hub.
Dehumidifier Running Cost Calculator FAQs
Do dehumidifiers use a lot of electricity?
No, not compared with heaters or tumble dryers. A typical compressor dehumidifier draws about 150 to 250 W, so 8 hours a day uses 1.2 to 2 kWh, around 32p to 53p at 26.32p per kWh. Desiccant models use roughly two to three times more.
How much does it cost to run a dehumidifier for a month?
A 200 W dehumidifier running 8 hours a day costs about £12.77 a month on average at 26.32p per kWh. Run it 24 hours a day and the cost triples to about £38. Enter your own wattage and hours for an exact figure.
Does laundry mode cost more to run?
Usually yes, because laundry mode runs the fan at full speed and keeps the dehumidifier going without pausing for the humidistat. Set Time it runs at full power to 100% and use the higher wattage from the manual if it lists one.
Where do I find my dehumidifier’s wattage?
Check the rating label on the back or base, or the specification page in the manual. It often gives power at a test condition such as 20 °C and 60% humidity. A plug in energy monitor shows what your machine draws in your home.
Is it cheaper to run a dehumidifier or open a window?
Opening a window costs nothing in electricity, but in cold weather it lets heat out, which you then pay to replace. Short bursts of ventilation after cooking and showering, plus a dehumidifier for stubborn damp, is often the most practical balance.
What humidity should I set my dehumidifier to?
Around 50% to 60% relative humidity suits most homes. Lower settings make the dehumidifier run for longer and cost more, with little extra benefit. Raise the setting slightly once condensation and musty smells have cleared.
Checked October 2026. Sources: Energy price cap unit rates and standing charges (Ofgem), Dehumidifier (Wikipedia).