Laundry and moisture
Dehumidifier Cost Calculator UK
Estimate the cost of running a compressor or desiccant dehumidifier for damp rooms, laundry drying or overnight use.
Estimated running cost
- Per hour
- 7.40p
- Per day
- 59.21p
- Per week
- £4.14
- Per month
- £17.76
- Per year
- £216.11
Formula: dehumidifier wattage ÷ 1,000 × hours used × electricity price.
Cost table
| Scenario | Power | Use time | Cost at 24.67p/kWh |
|---|---|---|---|
| 200W for 8 hours | 200W | 8 hours | 39.47p |
| 300W for 8 hours | 300W | 8 hours | 59.21p |
| 500W for 8 hours | 500W | 8 hours | 98.68p |
| 650W for 8 hours | 650W | 8 hours | £1.28 |
Formula
dehumidifier wattage ÷ 1,000 × hours used × electricity price = running cost
For example, a 300W dehumidifier used for 8 hours at 24.67p/kWh costs 0.3 x 8 x 24.67p = 59.21p.
Ways to reduce the cost
- Use laundry mode only when drying clothes, not as a permanent setting.
- Keep windows closed while the machine is running.
- Use a humidity target around 50-60% rather than running continuously.
- Clean filters so the unit does not work harder than needed.
FAQs
How much does a dehumidifier cost overnight?
A 300W unit running for 8 hours costs around 59p at 24.67p/kWh.
Do dehumidifiers use a lot of electricity?
Small compressor models often use a few hundred watts, while some desiccant models use more.
Is a dehumidifier cheaper than a tumble dryer?
Usually yes for drying clothes, but it is slower. Compare your actual wattages and drying times.
Should I run it all day?
Only if the humidity problem needs it. A humidistat or timer usually keeps costs lower.
Last reviewed 3 May 2026. Source: Ofgem energy price cap. Figures are estimates. Actual prices vary by region, supplier, tariff, payment method and meter type.