Dishwashers are a staple in most UK kitchens, but many people wonder whether they're an expensive luxury or actually cheaper than washing up by hand. The good news is that modern dishwashers are surprisingly efficient — often using less water and energy than manual washing, especially for larger households.
Quick Answer: Dishwasher Running Costs
Based on the UK average electricity rate of approximately 24.5p per kWh:
| Programme | Energy Per Cycle | Cost Per Cycle | Annual Cost (5 cycles/week) |
|---|---|---|---|
| Eco (50°C) | 0.7 – 0.9 kWh | 17p – 22p | £44 – £57 |
| Normal (55–65°C) | 1.0 – 1.4 kWh | 25p – 34p | £64 – £90 |
| Intensive (70°C+) | 1.5 – 2.0 kWh | 37p – 49p | £96 – £127 |
| Quick Wash (45°C) | 0.6 – 0.8 kWh | 15p – 20p | £38 – £51 |
Key takeaway: Running your dishwasher on the eco programme instead of the normal cycle saves approximately £20–£35 per year. The eco mode takes longer (typically 3–4 hours) but uses lower temperature water, consuming significantly less energy.
Dishwasher vs Hand Washing: Which Is Cheaper?
This is one of the most common kitchen debates. Research from the University of Bonn and the Energy Saving Trust consistently shows that a fully loaded dishwasher uses less water and energy than washing the same amount of dishes by hand:
| Method | Water Used | Energy Cost | Water Cost | Total Per Wash |
|---|---|---|---|---|
| Dishwasher (eco) | 9 – 12 litres | 17p – 22p | 5p – 6p | 22p – 28p |
| Dishwasher (normal) | 11 – 14 litres | 25p – 34p | 5p – 7p | 30p – 41p |
| Hand washing (running tap) | 40 – 60 litres | 20p – 40p* | 18p – 27p | 38p – 67p |
| Hand washing (filled bowl) | 8 – 12 litres | 5p – 10p* | 4p – 6p | 9p – 16p |
*Energy cost for hand washing depends on whether you use a gas or electric boiler to heat water.
The key variables are:
- Dishwasher load: A full dishwasher is almost always cheaper than hand washing the same quantity. A half-empty dishwasher may not be.
- Hand washing technique: Using a bowl of hot water is far cheaper than washing under a running hot tap.
- Hot water source: If your hot water comes from a gas boiler (6.5p/kWh), hand washing is cheaper to heat than if you have an electric immersion heater (24.5p/kWh).
How Dishwasher Energy Use Breaks Down
Like washing machines, the majority of a dishwasher's energy consumption goes to heating water:
- Water heating: 70–80% of total energy use
- Pump and spray arms: 10–15%
- Drying phase: 10–15% (if using heated drying)
- Control electronics: Less than 5%
This is why the eco programme saves so much energy — it heats water to a lower temperature (50°C vs 65°C+) and compensates with a longer washing time to achieve the same cleaning result.
Running Costs by Energy Rating
| Energy Rating | kWh Per Cycle (Eco) | Cost Per Cycle | Annual Cost (260 cycles) |
|---|---|---|---|
| A (best available) | 0.6 – 0.7 kWh | 15p – 17p | £38 – £44 |
| B | 0.7 – 0.85 kWh | 17p – 21p | £44 – £54 |
| C | 0.85 – 1.0 kWh | 21p – 25p | £54 – £64 |
| D | 1.0 – 1.2 kWh | 25p – 29p | £64 – £76 |
| E–G (older models) | 1.2 – 1.8 kWh | 29p – 44p | £76 – £115 |
Factors That Affect Dishwasher Running Costs
- Programme selected: Eco mode uses 30–50% less energy than intensive programmes.
- Water inlet temperature: Some dishwashers can connect to a hot water supply, reducing internal heating energy. However, most UK installations use cold fill only.
- Load size: Always run full loads. A half-load uses 80–90% of the energy of a full load.
- Drying method: Heated drying uses extra energy. Opening the door after the wash cycle and air-drying saves 10–15% of total cycle energy.
- Machine age: Dishwashers over 10 years old typically use 20–40% more energy than modern equivalents.
- Dishwasher size: Full-size (13-place) models are more efficient per item than slimline (9-place) models when fully loaded.
Tips to Reduce Dishwasher Running Costs
- Use the eco programme as your default — it's specifically designed to minimise energy while still cleaning effectively.
- Always run full loads — waiting an extra day to fill the dishwasher saves more than running two half-loads.
- Skip the pre-rinse — modern dishwashers and detergents don't require pre-rinsing. Just scrape off large food debris.
- Open the door to air-dry — instead of using the heated drying cycle, crack the door open after washing and let dishes air-dry.
- Use quality detergent — cheap tablets may require a hotter programme or re-washing, using more energy overall.
- Clean the filter monthly — a blocked filter reduces cleaning efficiency and may require re-running cycles.
- Descale regularly — limescale buildup (common in hard water areas) reduces heating element efficiency.
- Consider time-of-use tariffs — run the dishwasher overnight on a cheaper off-peak rate if your tariff allows it.
Standby Power Consumption
Most dishwashers draw 1–3W when plugged in but not running (for the clock display and standby circuits). Over a year at 2W continuous standby, that's 17.5 kWh or about £4.29 in wasted electricity. Switching off at the wall between uses eliminates this.
Calculate Your Exact Costs
Use our free energy cost calculator to work out exactly what your dishwasher costs to run based on your specific electricity rate. Check your machine's energy label or look up the model on the manufacturer's website for accurate kWh per cycle figures.