Dehumidifier running cost calculator
Estimate daily dehumidifier costs and compare the electricity used to dry one laundry load with a tumble dryer.
After you calculate
See your dehumidifier running costs
Add your dehumidifier power, running hours and electricity price, then calculate to see your results.
Annual running cost
Shown after calculationMonthly average
Shown after calculationElectricity use
Tariff breakdown
Full calculation
Uses your entered running hours and selected electricity tariff.
Understand your estimate
How it works
Enter electrical input watts, choose your tariff, then enter daily running hours. Economy 7 separates the night-priced hours from the remaining day-priced hours and uses your own prices for each. Compressor and desiccant types do not have a fixed assumed power.
For laundry, enter drying hours per load and the dryer's full-cycle kWh. Use separate electricity rates if the appliances run in different tariff periods.
The running-cost view follows a daily schedule. The laundry view follows one drying load. Check which view is open before entering hours, because those time periods are different. A load spread over several sessions can have more total hours than one day's schedule.
- Check the power
Use the input watts for your actual appliance and setting.
- Match the hours
Separate daily running hours from drying hours for one load.
- Read the comparison
Check running costs or compare the two laundry methods per load.
- A measured average can better reflect cycling than a maximum power rating.
- Compare similar laundry quantities and dryness levels. The tool compares electricity costs, not drying performance.
A few good questions
Before youget started.
Understand this calculator, the figures to enter and the limits of your estimate.
Sources
- Energy price cap unit rates and standing chargesChecked on 9 October 2026
- Last checked
- 14 October 2026
- Rates as of
- 1 October 2026
EnergySums
Dehumidifier running cost calculator
United Kingdom · How it works
- Guide updated
- 14 October 2026
- Rates as of
- 1 October 2026
| Item | Value |
|---|---|
| Guide updated | 14 October 2026 |
| Rates as of | 1 October 2026 |
How it works
Enter electrical input watts, choose your tariff, then enter daily running hours. Economy 7 separates the night-priced hours from the remaining day-priced hours and uses your own prices for each. Compressor and desiccant types do not have a fixed assumed power.
For laundry, enter drying hours per load and the dryer's full-cycle kWh. Use separate electricity rates if the appliances run in different tariff periods.
The running-cost view follows a daily schedule. The laundry view follows one drying load. Check which view is open before entering hours, because those time periods are different. A load spread over several sessions can have more total hours than one day's schedule.
- Check the power
Use the input watts for your actual appliance and setting.
- Match the hours
Separate daily running hours from drying hours for one load.
- Read the comparison
Check running costs or compare the two laundry methods per load.
- A measured average can better reflect cycling than a maximum power rating.
- Compare similar laundry quantities and dryness levels. The tool compares electricity costs, not drying performance.
Formula
Electricity prices are in pence per kWh; divide by 100 for pounds.
Changing the electricity price changes the cost, while leaving the entered energy use unchanged. A positive laundry saving means the dehumidifier costs less for these inputs. A negative saving means the tumble dryer costs less. Neither result tells you which method will dry faster.
Read the result with its time label. A daily running cost and a cost for one laundry load cover different amounts of use. If you change the drying time, keep the laundry quantity and target dryness comparable. A cost saving can come from fewer running hours, a lower power input or a different electricity price.
- Energy / day
- (Power (W) ÷ 1,000 W/kW) × hours/day= kWh/day
- Economy 7 cost / day
- (Power (W) ÷ 1,000 W/kW) × (day hours × day price (p/kWh) + night hours × night price (p/kWh)) ÷ 100 p/GBP= daily cost in pounds
- Cost / year
- Daily kWh × 365 days × electricity rate (p/kWh) ÷ 100 p/GBP= annual cost
- Monthly average
- Annual cost/year ÷ 12 months/year= monthly cost
- Dehumidifier / load
- (Power (W) ÷ 1,000 W/kW) × drying hours × its rate (p/kWh) ÷ 100 p/GBP= load cost
- Dryer / load
- Full-cycle kWh × dryer rate (p/kWh) ÷ 100 p/GBP= load cost
- Difference / load
- Dryer cost − dehumidifier cost= saving with dehumidifier
| Calculation | Formula with saved values | Result |
|---|---|---|
| Energy / day | (Power (W) ÷ 1,000 W/kW) × hours/day | kWh/day |
| Economy 7 cost / day | (Power (W) ÷ 1,000 W/kW) × (day hours × day price (p/kWh) + night hours × night price (p/kWh)) ÷ 100 p/GBP | daily cost in pounds |
| Cost / year | Daily kWh × 365 days × electricity rate (p/kWh) ÷ 100 p/GBP | annual cost |
| Monthly average | Annual cost/year ÷ 12 months/year | monthly cost |
| Dehumidifier / load | (Power (W) ÷ 1,000 W/kW) × drying hours × its rate (p/kWh) ÷ 100 p/GBP | load cost |
| Dryer / load | Full-cycle kWh × dryer rate (p/kWh) ÷ 100 p/GBP | load cost |
| Difference / load | Dryer cost − dehumidifier cost | saving with dehumidifier |
- A positive difference means lower dehumidifier electricity cost.
- Standing charges are excluded. Annual figures hold the daily schedule and price constant.
- Day hours = total daily hours − night-priced hours. For laundry, use its own day/night hour split with the same prices; the dryer retains its separately entered price.
Worked example
Illustrative 200 W appliance at the Great Britain average Direct Debit rate for 1 October 2026 to 31 December 2026.
Illustrative Economy 7 prices of 32p day and 12p night: 200 W running for eight hours, including six night-priced hours, costs £0.128 in the day plus £0.144 at night = £0.272/day, or £99.28/year. These are editable example prices, not published tariff defaults.
- Daily running
- 8 hours/day
- Electricity rate
- 26.32 p/kWh
- Laundry session
- 6 hours/load
- Dryer cycle
- 1.5 kWh/load
| Item | Value |
|---|---|
| Daily running | 8 hours/day |
| Electricity rate | 26.32 p/kWh |
| Laundry session | 6 hours/load |
| Dryer cycle | 1.5 kWh/load |
- Energy / day
- 200 W ÷ 1,000 W/kW × 8 hours= 1.6 kWh
- Cost / year
- 1.6 kWh × 365 days × 26.32 p/kWh ÷ 100 p/GBP= £0.00
- Monthly average
- £0/year ÷ 12 months/year= £0.00
- Dehumidifier / load
- 200 W ÷ 1,000 W/kW × 6 hours × 26.32 p/kWh ÷ 100 p/GBP= £0.32
- Dryer / load
- 1.5 kWh × 26.32 p/kWh ÷ 100 p/GBP= £0.39
- Saving / load
- (1.5 − 1.2) kWh × 26.32 p/kWh ÷ 100 p/GBP= £0.08
| Calculation | Formula with saved values | Result |
|---|---|---|
| Energy / day | 200 W ÷ 1,000 W/kW × 8 hours | 1.6 kWh |
| Cost / year | 1.6 kWh × 365 days × 26.32 p/kWh ÷ 100 p/GBP | £0.00 |
| Monthly average | £0/year ÷ 12 months/year | £0.00 |
| Dehumidifier / load | 200 W ÷ 1,000 W/kW × 6 hours × 26.32 p/kWh ÷ 100 p/GBP | £0.32 |
| Dryer / load | 1.5 kWh × 26.32 p/kWh ÷ 100 p/GBP | £0.39 |
| Saving / load | (1.5 − 1.2) kWh × 26.32 p/kWh ÷ 100 p/GBP | £0.08 |
- Both drying methods use the same illustrative rate here. Your own times, cycle energy and prices may differ.
- Money is rounded for display; totals use unrounded values.
Assumptions and limits
- Entered power stays constant. Humidity controls and cycling can change actual use; use a measured average when available.
- The tool does not predict water removal, humidity, room temperature or drying time.
- Laundry costs exclude other drying aids, heating, ventilation, purchase costs and wear. Add separately calculated energy from any extra devices.
- Economy 7 daily night-priced use cannot exceed seven hours. Drying loads may span multiple sessions or nights; enter their actual total night-priced hours rather than applying the daily limit to a whole load.
Country rules
Published single-rate prices use the stored Ofgem table for your region and payment method in Great Britain. Check the period against your bill. Published electricity defaults include 0% VAT for this period. Use your own price if the table does not match your tariff. The estimate leaves out standing charges because it shows the dehumidifier's electricity use, rather than your whole bill.
- Economy 7 day/night prices and clock times come from your supplier. A blended multi-register cap is not a universal night price.
- Day/night prices are editable personal inputs from your bill, supplier quote or another known source. Enter a price only for periods used by the daily or laundry schedule. Prices must include applicable tax.
- Annualised costs hold the selected rate constant and do not predict later cap changes.
When to ask a professional
Keep any measured power reading and the drying routine used in your comparison. These help explain the assumptions when you discuss the result.
- Energy adviser: help with tariffs and high consumption.
- Building professional: advice on persistent damp that this cost estimate cannot diagnose.
- Follow the maker's placement and clearance instructions, including use near laundry. The tool does not prescribe humidity targets.
Questions and answers
| Question | Answer |
|---|---|
| Are dehumidifiers expensive to run? | The electricity cost depends on watts, hours and your price per kWh. Calculate your own routine, including the actual setting or measured average power, rather than using a fixed cost for every model. |
| How much electricity does a dehumidifier use? | At constant input power, 200 W for eight hours uses 1.6 kWh. This is an illustrative calculation, not a typical value for every compressor or desiccant model. |
| Is it worth running a dehumidifier all the time? | This tool can estimate the cost of continuous running, but cannot decide whether it is needed. Follow its manual and consider the moisture source, room conditions and humidity controls. |
| Which is cheaper, a dehumidifier or a heated airer? | Compare the full electricity used for a similar drying load. Use the appliance calculator for the airer's watts and hours, including other electrical devices used to help dry the clothes. |
| Is a dehumidifier cheaper than a tumble dryer for drying clothes? | Open Compare drying and enter the dehumidifier session time, dryer energy per load and both electricity rates. A lower cost does not mean the two methods provide the same drying time or result. |
Sources
| Source | Checked | Reference URL |
|---|---|---|
| Energy price cap unit rates and standing charges | 9 October 2026 | https://www.ofgem.gov.uk/information-consumers/energy-advice-households/get-energy-price-cap-standing-charges-and-unit-rates-region |