Dehumidifier running costs
Running cost depends on the unit's power draw, how long it runs, and your electricity price.
The formula
Cost per hour = watts ÷ 1000 × price per kWh.
At the October 2026 price cap electricity rate of 26.32p/kWh (October 2026 price cap, as quoted by Which?), a 200 W unit costs about 5.3p per hour. A 500 W unit costs about 13.2p per hour.
Cost per litre
Divide cost per hour by litres removed per hour (rated L/day ÷ 24). This is our "cheapest to run" measure. It is only a guide, because units don't run at their rating all the time and drying slows as the air gets drier.
Which wattage we use
We use the maximum power figure where one is listed, and otherwise the typical figure. Some units use more power when a heater or laundry mode is on.
Cutting the cost
- Use a humidistat or auto setting where available, so the unit cycles off.
- Close doors and windows in the room being dried.
- Choose the right size. See what size.
Try the running cost calculator. Price source: Which? coverage of the October 2026 energy price cap.