Dehumidifier Running Cost Calculator
See what your dehumidifier could add to your electricity costs. Use its power and active running time, or enter measured energy use for a closer estimate. Add the unit price from your bill and choose the number of operating days you want to check.
Check your running cost
240 W and 6 hours are editable examples. Enter the electricity rate from your own bill. All calculations run in your browser.
| Scenario | kWh / day | Period kWh | Cost / day | Period cost | Cost / active hour |
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Updated 7 October 2026
How to choose a dehumidifier: size, type and cost →How to use the calculator
Choose the input method that fits your information. Power mode uses watts and active hours per day. Measured-energy mode uses the kWh recorded during a stated period. Enter your tariff in the unit shown beside the field, then choose the days you want to estimate.
If you compare two scenarios, check both input sets. Changing a rate or schedule changes the answer; it does not prove that one machine performs the same task more efficiently.
Watts, kilowatts and kilowatt-hours
Watts describe power. Dividing by 1,000 converts watts to kilowatts. Multiplying kilowatts by hours gives kilowatt-hours, the energy quantity used in the cost calculation.
A 240 W draw sustained for six hours uses 1.44 kWh. At an illustrative £0.30/kWh, that costs £0.432. Thirty identical operating days cost £12.96.
When measured energy is more useful
Use a full-day or multi-day kWh reading when the machine changes its power draw or cycles. Do not apply another active-runtime percentage to measured total energy: the reading already includes the operation during that period.
A projection assumes similar future use. Check a different period if the room, setting or season changes.
Why the result is not your complete electricity bill
The result covers the entered energy at the entered unit price. It does not automatically include standing charges, taxes, delivery fees, demand charges or another appliance's use. For time-of-use electricity, calculate the energy used at each rate separately rather than pricing all hours at one rate.
Common input mistakes
A pence-versus-pounds error can multiply a result by 100. Confusing plugged-in hours with active hours can also overstate consumption. Check the tariff unit, the power source and the operating days before comparing results. A zero-cost result may simply mean you entered zero hours, energy or rate.
Frequently asked questions
Where do I find the wattage?
Check the appliance label, manual or manufacturer's specifications. If the quoted number is a maximum rating, keep that limitation with your estimate. A measured kWh reading may be more representative of use.
Can I use dollars or euros?
Yes, currency changes the result label. It does not convert an electricity tariff or money between currencies. Enter the matching price from your own bill.
Does a cheaper scenario prove a saving?
It shows an arithmetic difference between the entered scenarios. Actual savings need comparable performance and representative use; the tool cannot verify those conditions.
Method
Power mode: watts ÷ 1,000 × active hours/day × operating days × tariff. Measured mode: measured kWh ÷ measurement days × operating days × tariff. Both produce estimates for stated inputs, without automatic device power or local tariff assumptions.