How Much Electric
Does a Slow Cooker Use?
Slow cookers are one of the cheapest cooking appliances in any UK kitchen. The honest 2026 figure is 20p to 60p per cook session plus roughly £10 to £25 per year for typical weekly use. The same meal in an oven costs 3 to 5 times more.
A typical UK slow cooker draws 100 to 350 watts depending on size plus setting. At the current Q2 2026 Ofgem unit rate of 24.7p per kWh, an 8-hour low cook uses 0.8 to 1.6 kWh, costing 20p to 40p per session. A 4-hour high cook uses 0.6 to 1.2 kWh (15p to 30p). Larger 6L plus 8L slow cookers reach 60p per session at the high setting. Across a year of weekly use, slow cookers cost roughly £10 to £25 in total electricity, far less than equivalent oven cooking which would cost £45 to £80 for the same number of meals.
The figures that matter
Typical wattage
Range across 1.5L to 8L UK domestic slow cookers.
8hr low cook
Standard 8-hour low-setting cook on an average UK slow cooker.
Average per cook
Real-world energy use across a typical full meal cycle.
vs oven
Slow cookers use roughly one-fifth the energy of a conventional oven for the same meal.
Four things to consider
Low wattage by design
Slow cookers operate at a fraction of oven power. Long cook time but minimal load.
Sealed lid retains heat
Heat loss is minimal. The pot recycles its own steam plus heat through the cycle.
Resist lifting the lid
Each lid removal lets out roughly 15 minutes worth of heat. Adds slightly to cycle time plus cost.
Match size to meals
An 8L cooker for one person wastes energy heating empty space. A 3.5L is more efficient for solo cooking.
Why slow cookers are so cheap to run
Slow cookers work by holding a low temperature for a long time. The heating element is rated at a fraction of what an oven heating element draws. A typical UK fan oven runs at 2 to 3 kW. A typical slow cooker runs at 0.1 to 0.35 kW. Even running for ten times as long, the slow cooker uses far less electricity overall.
Real numbers at 24.7p per kWh (Q2 2026 Ofgem cap):
- Compact 1.5 to 3.5L slow cooker (150W). 0.6 to 1.2 kWh per cook. 15p to 30p per session.
- Medium 4.5 to 5.5L slow cooker (200W). 0.8 to 1.6 kWh per cook. 20p to 40p per session.
- Large 6 to 6.5L slow cooker (250 to 280W). 1 to 2 kWh per cook. 25p to 49p per session.
- Extra-large 7 to 8L slow cooker (300 to 350W). 1.2 to 2.4 kWh per cook. 30p to 60p per session.
- Equivalent oven dish at 2.5kW for 90 minutes. 3.75 kWh, 92.6p per session.
The hidden saving versus oven cooking. The numbers above only count the heating element. An electric oven also warms the kitchen which then competes with whatever ambient heating is running. A slow cooker generates very little ambient heat. In summer this matters because oven cooking forces additional cooling load.
Where slow cookers can run more expensive:
- Models with a digital display plus standby mode draw 1 to 2W continuously when plugged in. Across a year that is 9 to 18 kWh of phantom load (£2 to £4).
- Larger 6.5L plus 8L cookers have higher heating elements (300 to 350W). Per-session cost rises proportionally.
- Cooking thinner liquids requires the lid to seal properly. A loose-fitting lid lets steam escape plus the element cycles longer.
- Half-empty cookers waste energy heating air space they cannot use efficiently.
The wattage label rule. Always check the wattage on the underside or back of the slow cooker. Manufacturers vary the rating significantly. A premium-brand 6L cooker might be 250W. A budget 6L cooker might be 360W. The cheaper model could cost 40 percent more in electricity over its lifetime.
Real number ranges
Cost per cook session by slow cooker size (UK 2026)
A typical 8-hour low slow cook
Element on full
Slow cooker pulls full rated wattage to bring contents up to 80 to 90°C. Roughly 30 to 40 minutes.
Reaches temperature
Element starts cycling on plus off to maintain temperature. Average draw drops to around 60 percent of rated.
Steady simmer
Cycling continues. Real average draw 50 to 70 percent of rated. Total energy use accumulating slowly.
Done
Total session draw 0.8 to 2 kWh depending on cooker size. Cost: 20p to 60p at current Ofgem rate.
Four ways to get the most from a slow cooker
Match cooker size to meals
A 3.5L for couples or solo cooking. 5 to 6L for families. 8L only for batch cooking 6+ portions.
Use the low setting where possible
Most recipes work fine on low. Longer cook time still uses less total energy than fast oven cooking.
Switch off at the wall after use
Digital-display models draw 1 to 2W on standby continuously. Switched extension lead eliminates this.
Use lid plus do not peek
Each lid lift adds 15 to 20 minutes to cook time. Trust the recipe.
Compare the options
Slow cooker (medium 5L)
- ✓200W rated wattage with cycling actual draw.
- ✓20p to 40p per cook session on low for 8 hours.
- ✓Hands-off cooking. Set in the morning, eat in the evening.
- ✓Minimal kitchen ambient heat. No competition with summer cooling.
- ✓Annual cost roughly £10 to £25 for weekly use across the year.
Conventional electric oven
- ✗2 to 3kW rated wattage with frequent element cycling under load.
- ✗80p to £1 per typical 90-minute dish at the same Ofgem cap rate.
- ✗Active monitoring needed. Set timers, check progress, adjust as you go.
- ✗Significant ambient heat. Kitchen plus surrounding rooms warm up during use.
- ✗Annual cost £100+ for similar meal frequency as weekly slow cooker use.
Slow cookers are one of the easiest energy wins in any UK kitchen. Our full Appliances hub covers running costs across every major UK household appliance.
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This article is one chapter inside our complete Appliances knowledge base. The hub covers running costs across every major household appliance from kettles to heat pumps.
More on appliance running costs
Three further kitchen appliance articles in the same hub group cover related questions. The first is how much electric does a crock pot use for the brand-name equivalent term. The second covers how much electricity does an air fryer use for the modern alternative. The third is how much electricity does a kettle use for the kitchen baseline.