Calculating tumble dryer running cost
The formula is simple:
Cost per cycle = kWh used x unit rate (p/kWh) / 100
The two variables you need:
1. How many kWh your dryer uses per cycle. Check the product specification page or your model's energy label. If you cannot find it:
- Condenser tumble dryer: assume 2.5kWh per cycle (UK tested average)
- Vented tumble dryer: assume 2.5kWh per cycle
- Heat pump tumble dryer: assume 1kWh per cycle
2. Your current unit rate. Check your electricity bill or your Octopus Agile app. For live Agile rates in your region, check AgileAlert now. The rate changes every 30 minutes on Agile.
A Tapo P110 smart plug (around £12) measures actual energy consumption per cycle for your specific machine. Running your dryer through it once gives you the precise kWh figure for your model rather than the industry average.
Condenser: cost per cycle at all tariff scenarios
A condenser tumble dryer using 2.5kWh per cycle costs:
- Price cap (26.11p/kWh): 65p per cycle
- Agile peak (38p/kWh): 95p per cycle
- Economy 7 overnight (11p/kWh): 28p per cycle
- Agile overnight average (4p/kWh): 10p per cycle
- Agile plunge pricing (0p/kWh): 0p per cycle
The 95p peak Agile figure assumes the dryer runs entirely within a peak pricing half-hour. In practice, a 90-minute cycle spans multiple 30-minute slots. If those slots vary between 20p and 45p, the blended average cost per cycle is typically 55-75p during a peak evening. The 95p figure represents the worst-case scenario: running during the most expensive single window.
Heat pump: cost per cycle at all tariff scenarios
A heat pump tumble dryer using 1kWh per cycle costs:
- Price cap (26.11p/kWh): 26p per cycle
- Agile peak (38p/kWh): 38p per cycle
- Economy 7 overnight (11p/kWh): 11p per cycle
- Agile overnight average (4p/kWh): 4p per cycle
- Agile plunge pricing (0p/kWh): 0p per cycle
At overnight Agile rates, each drying cycle costs 4p. That is less than the cost of boiling a kettle for a cup of tea.
Annual cost comparison
The table below shows annual running cost for both dryer types across all key tariff scenarios, at 250 cycles per year (the UK average of 4-5 loads per week).
| Tariff | Rate | Condenser per cycle | Condenser annual | Heat pump per cycle | Heat pump annual |
|---|---|---|---|---|---|
| Price cap | 26.11p | 65p | £163 | 26p | £65 |
| Agile peak | 38p | 95p | £237 | 38p | £95 |
| Economy 7 night | 11p | 28p | £69 | 11p | £28 |
| Agile overnight | 4p | 10p | £25 | 4p | £10 |
| Agile plunge | 0p | 0p | £0 | 0p | £0 |
The biggest single saving available to the average UK household is moving from peak pricing to overnight Agile timing on their existing condenser dryer: from £237 to £25, a saving of £212 per year. That is a weekend break. Four months of broadband. A new pair of shoes every other month.
Weekly and monthly cost reality check
Numbers become real when you break them into familiar units. Here is what 4 loads per week actually costs, month by month:
- At peak Agile (38p): £15.20 per month - That is two cinema tickets every month just to run the dryer at the wrong time of day.
- At price cap (26.11p): £10.40 per month - Still adding up, especially alongside other household appliances.
- At overnight Agile (4p): £1.60 per month - Essentially noise in the household budget. Less than a single coffee.
The difference between running at peak and running overnight: £13.60 per month. That is a meal out. Half a tank of petrol. A weekly shop's worth of difference over two months.
How to achieve overnight pricing: check AgileAlert each evening for your region's cheapest overnight window, then set the delay start on your dryer accordingly. It takes under two minutes. The monthly saving pays for that two minutes about 400 times over.
For a complete guide to setting delay start on your specific dryer brand, see the all-brands delay start guide.
What about part-loads and drying time?
The 2.5kWh figure is for a standard full cotton load. In practice:
- A half-load uses approximately 70% of the full-load energy (not 50%), because the machine still needs to reach operating temperature.
- A mixed synthetics load uses approximately 1.5-2kWh, because synthetic fabrics dry faster at lower temperatures.
- Adding too many items increases drying time and total energy, sometimes reaching 3kWh for an overloaded drum.
The practical implication: batch laundry into full loads. A full load costs 10p overnight. Two half-loads cost approximately 14p overnight. Over a year of 4 loads per week, that 40% inefficiency from half-loading adds around £10 in unnecessary cost. Not enormous, but easily avoidable.
For the full picture of how timing decisions interact with usage frequency and dryer type, see the complete tumble dryer timing guide.