Air fryer or slow cooker: which costs less to run?

There’s nothing better than a hearty meal to soothe the soul, but cooking for hours isn’t quite as appealing as it used to be. Now, we’re so conscious of the amount of energy being used by appliances that the things that used to be simple pleasures now have a higher level of scrutiny placed on them.

Nobody wants to feel under pressure to just enjoy a simple meal, though. So, it’s unsurprising that savvy chefs seeking other ways to cook are looking beyond their traditional ovens.

And there are two main appliances vying for a spot on our kitchen countertops, but which costs less to run, an air fryer or slow cooker?

How to choose the best slow cooker

Nothing else keeps food simmering at low temperature like a slow cooker (or crockpot). When you’re thinking about how to choose the best slow cooker, energy consumption and capacity should be high on the list.

A basic slow cooker can be bought for as little as £18, or you can pay in excess of £100 for a premium model. 

More expensive slow cookers have extra features, such as auto cook or sear functions, but these are more for ease of use and aren’t necessary – a deliciously slow-cooked meal can be accomplished with even the most basic model.

Slow cookers come in oval or circular shapes. Whole chickens and large pieces of meat such as brisket or shoulder fit better in an oval-shaped slow cooker, while a round-shaped model is well suited for soups, stews and casseroles.

For one or two people, a slow cooker with a capacity of 3 litres is ideal. Bear in mind that slow cookers work best when not full and the actual usable capacity of a model is around two thirds of its stated capacity. So, for a slow cooker that boasts a capacity of 3.5 litres, the usable cooking space will only be around 2 litres.

Some other useful features to look out for include a glass lid, to see how the cooking is progressing without losing any heat.

You might also want to invest in a model with a timer that helps to avoid overcooking the food by switching to a ‘keep warm’ mode if you won’t be home when it finishes (we love this function – it’s great for overnight slow-cooking too).

How much energy does a slow cooker use?

Until recently, no other one-stop-shop small kitchen appliance could create healthy meals, such as a chickpea and bean masala or melt-in-the-mouth pork joint, using such small amounts of energy as a slow cooker.

But just how much energy does a slow cooker use? Although it takes longer to cook food, slow cookers can use less than a tenth of some electric ovens, according to a recent Uswitch investigation into energy-efficient cooking.

Electricity costs are currently capped at 22p per kWh, though some fixed tariff deals may be lower, meaning that using a slow cooker would cost on average 29p per meal.

If you were to run a traditional oven for eight hours it could cost you more than a fiver, and to run an electric grill or hob for the same amount of time could cost more than £4.

A microwave fares slightly better, costing £1.23, but still nowhere near as efficient as a slow cooker. Even if you average it out (nobody is using an oven for eight hours...) it’s still not cheaper – plus you don’t get the delicious succulence you do from slow cooking.

Most slow cookers have three or four different settings: high, low, warm and automatic. These modes control the amount of time it takes for the food to reach a point where it’s simmering before the slow cooker stabilises and continues to cook at that temperature.

So, dishes cooked on a high setting may only take four hours, whereas meals prepared on the low setting could take eight hours.

The average amount of electricity used by slow cookers is between 75–150W on low, and 150–210W on high.

Using the current energy price, this could mean cooking your meal on a low setting for eight hours at 150W would cost just under 27p, whereas cooking for the same amount of time on a high setting (at 210W) could cost just over 37p.

What is an air fryer?

An air fryer is a countertop appliance that uses rapid air circulation instead of oil to heat food to super-high temperatures in a short amount of time.

Thanks to its reduced oil capacity (some recipes only need a 1–2 teaspoons), air fryers are incredibly easy to keep clean. Even top chefs are using them at home.

But the real bonus is that they use much less energy than electric, gas and fan-assisted ovens – and that’s why they’ve been enjoying a moment in the spotlight.

A BBC Radio 4 experiment found that the best air fryers use less than half of the energy needed to cook a chicken or jacket potato in a traditional oven.

A 2-litre to 4- or 5-litre capacity air fryer is plenty for a small household. That’s ideal if there are only two diners at home, but when it comes to entertaining and creating larger meals for more people, the energy use (and cost) will of course creep up.

The average air fryer wattage is 1.5kW, and if it were used for 60 minutes (at 22p per kWh) it would cost 33p to run.

However, a typical air fryer recipe may only call for 25 minutes’ use, meaning a meal could cost as little as 16p.

Which costs less to run?

So to the important answer, which appliance costs less to run, an air fryer or slow cooker?

The average meal costs less to cook in an air fryer than a slow cooker (16p versus 27p), so when it comes to choosing an air fryer or slow cooker to cook your meals, an air fryer is the more cost effective option.

It’s worth noting with an air-fried dinner you might need to be cooking accompanying ingredients separately (by boiling, perhaps), or using the same air fryer again to cook your veg, for example.

This blog shows you how to air fry virtually any vegetable (timings can be between 10–30 minutes depending on the veg, so add between 6–17p onto the costs of the recipes we’ve mentioned).