Drying washing indoors is one of the few household costs you can work out almost exactly. An appliance’s wattage, the hours you run it and your electricity rate are all you need — so instead of guessing whether a heated airer really is cheaper than the tumble dryer, you can put your own numbers in and see.
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Running cost is simply watts ÷ 1,000 × hours × your unit rate. On the current UK price cap of 26.11p per kWh, a 300W heated airer left on for five hours costs about 39p a load; a 2,500W condenser tumble dryer running for two hours costs about £1.31. A heat-pump dryer sits between them. The unheated airer is free to run but puts all that moisture into your flat, which is its own problem.
Editorial note: BetterFlat is an independent UK home advice website. This calculator uses the electricity unit rate from the Ofgem price cap and typical appliance wattages, all of which you can edit. It is a guide to relative costs, not a bill estimate — your own tariff, appliance and drying times will differ.
| Drying method | Watts | Hours per load |
Per load | Per week | Per year |
|---|---|---|---|---|---|
| Unheated airer or clothes horse Free to run, but the moisture goes into your flat — pair with ventilation or a dehumidifier. |
— | — | — | ||
| Heated airer (no cover) Typical 2-3 tier heated airer left on until dry. |
— | — | — | ||
| Heated airer with a cover The cover traps heat, so the same airer finishes noticeably sooner. |
— | — | — | ||
| Dehumidifier on laundry mode Compressor models in a closed room; also protects the room from damp. |
— | — | — | ||
| Heat-pump tumble dryer Slowest of the dryers but by far the cheapest to run. |
— | — | — | ||
| Condenser tumble dryer No outside vent needed, which is why flats often end up with one. |
— | — | — | ||
| Vented tumble dryer Fastest, but needs somewhere to vent the hose. |
— | — | — |
Every figure is editable. Check the rating plate or manual for your own appliance’s wattage and put your real numbers in — the defaults are typical values, not measurements of a specific model.
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What actually brings that cost down
Two things move this number more than anything else. Drying on a heated airer instead of a tumble dryer cuts the running cost sharply, and a dehumidifier running alongside it pulls the moisture out of the room so it does not end up on your windows as condensation.
Status Heated Airer — check price →MeacoDry Arete One 12L — check price →
Full comparisons: Best heated clothes airers · Best dehumidifiers for drying clothes
How the calculation works
There is no clever modelling here, which is the point. The formula is:
(watts ÷ 1000) × hours × (pence per kWh ÷ 100) = cost per load in £
The default rate of 26.11p per kWh is the Ofgem price cap for a standard variable Direct Debit tariff in England, Scotland and Wales from 1 July to 30 September 2026. From 1 October to 31 December 2026 it rises to 26.32p. Standing charges are left out deliberately — you pay those whether you dry any washing or not, so including them would flatter nothing and confuse the comparison. If you are on a fixed or time-of-use tariff, put your real rate in the box.
The default wattages are typical for each appliance type rather than measurements of a particular model, and drying times assume a normal mixed load. Both matter enormously: a heated airer used with a cover finishes far sooner than the same airer without one, which is why they appear as separate rows.
What the numbers actually tell you
Three things tend to surprise people who run this.
Wattage matters less than hours. A low-wattage appliance left on all day can cost more than a thirsty one that finishes quickly. This is why covers, spin speeds and airflow do more for your bill than shopping for a lower-wattage airer.
The cheapest option is rarely the cheapest overall. An unheated airer costs nothing to run, but a load of washing releases a couple of litres of water into your flat. In a cold, poorly ventilated room that shows up as condensation on the windows and, eventually, mould in the corners. The running cost of a dehumidifier is partly the price of not creating a damp problem.
Tumble dryers are not one thing. The gap between a heat-pump dryer and an older vented or condenser model is usually larger than the gap between a heat-pump dryer and a heated airer. If a dryer is the only realistic option for your household, the type you choose matters more than whether you use it.
Tumble dryerAirer or dehumidifier
Run times are typical rather than guaranteed — a cold, unventilated room takes longer. An unheated airer costs nothing to run, but the water goes into your flat instead of up a vent.
Rate: 26.32p per kWh (Ofgem price cap, 1 October to 31 December 2026). Tumble dryer consumption: full cotton cycle. Wattages: manufacturer specifications for the models recommended in this guide.
Common questions
How much does a heated clothes airer cost to run in the UK?
Most heated airers draw between 100W and 300W. At the current price cap rate of 26.11p per kWh, a 300W airer run for five hours costs roughly 39p, and a 100W model roughly 13p. Adding a cover typically cuts the drying time rather than the wattage, which is where the saving comes from.
Is a heated airer cheaper than a tumble dryer?
On a per-load basis, almost always yes — a heated airer draws a fraction of the power of a tumble dryer, even though it runs for longer. The gap narrows against a modern heat-pump dryer, which is far more efficient than an older vented or condenser model. Put your own appliance wattages into the calculator above to see the difference for your household.
Does a dehumidifier make drying clothes cheaper?
A dehumidifier does not dry clothes on its own, but in a closed room it speeds up an unheated or heated airer considerably and removes the moisture that would otherwise settle on your walls and windows. Treat its running cost as buying both faster drying and damp protection, rather than comparing it head-to-head with a dryer.
Should I include the standing charge in the cost?
No. The daily standing charge is payable whether or not you dry any washing, so it is not part of the cost of a load. It matters for your overall bill, not for choosing between drying methods.
What electricity rate should I use?
If you are on a standard variable tariff, the price cap rate is a reasonable default — 26.11p per kWh to 30 September 2026, rising to 26.32p from 1 October. If you are on a fixed deal, an Economy 7 tariff or anything time-of-use, use the rate from your own bill, because it can differ substantially.