With cooking costs high on people's minds this winter, we headed to the lab to find out how much it costs to cook a roast dinner.
We pitted a range of kitchen appliances against each other, calculating how long it took, how much energy we used and, crucially, how much it cost. Here’s what we found.
Our lab testers used several smaller kitchen appliances, including a microwave, an air fryer, a pressure cooker and a halogen oven, and compared them against a built-in electric oven and an induction hob.
We cooked food you'd find on a Sunday lunch table, including roast chicken, roast potatoes and steamed vegetables.
We recorded how long each dish took to cook, how much electricity they used and how much it cost. We also rated each dish out of five for the quality of cooking.
See more cooking cost comparisons in our guide to the cheapest ways to cook.
Roast chicken cooking costs compared
| Built-in electric oven | Pressure cooker | Air fryer | Slow cooker | Halogen oven | |
| Cooking time | 76 minutes | 32 minutes | 53 minutes | 180 minutes | 54 minutes |
| Energy used to cook | 1.16 kWh | 0.34 kWh | 0.54 kWh | 0.9 kWh | 1.17 kWh |
| Cost to cook | 39p | 11p | 18p | 31p | 40p |
| Saving compared to oven | N/A | 28p cheaper | 21p cheaper | 8p cheaper | 1p more |
| Quality of cooking | 4 - meat was a little dry; skin crispy and browned | 4 - cooked rather than roasted; skin not crispy | 5 - juicy, flavoursome meat; crispy brown skin | 4 - well cooked; skin only slightly crisped | 5 - full of flavour with a crispy skin |
Our verdict: roast chicken
Cheapest appliance: air fryer
Best overall: air fryer for a small chicken; oven for bigger birds
The pressure cooker was the quickest and cheapest way of cooking the chicken, but it didn’t give the distinctive crispy skin that the other appliances did.
The air fryer cooked a perfect roast chicken, and cost only 18p. The oven cost 39p to cook a delicious looking roast chicken, although the meat was a little dry. The oven does have the advantage of size over the other appliances - if you’re cooking for a larger group you may find your bird doesn’t fit in the air fryer or pressure cooker.
It's worth bearing in mind that if you’re turning your oven on to cook one item, it’s likely to be most efficient to cook as much as possible in the oven, rather than using lots of separate appliances or doing several air fryer batches.
For more on deciding between the two, watch our video comparing ovens and air fryers.
Roast potato cooking costs compared
| Built-in electric oven | Air fryer | Halogen oven | Pressure cooker | Slow cooker | |
| Cooking time | 65 minutes* | 33 minutes | 25 minutes | 25 minutes | 180 minutes |
| Energy used to cook | 1.25 kWh* | 0.4 kWh | 0.51 kWh | 0.59 kWh | 0.9 kWh |
| Cost to cook | 43p | 14p | 17p | 20p | 31p |
| Saving compared to oven | N/A | 29p cheaper | 25p cheaper | 23p cheaper | 12p cheaper |
| Quality of cooking | 4.5 - crispy on the outside, soft on the inside | 4.5 - uneven browning; crispy skins; soft, fluffy insides | 4 - well cooked but only crispy on the top | 5 - crispy skins; soft, tender inside | 4 - well cooked but only crispy on one side |
* Time and energy usage include par-boiling the potatoes on the hob before putting them in the oven.
Our verdict: roast potatoes
Cheapest appliance: air fryer
Best overall: pressure cooker
The air fryer was the cheapest for cooking our roast potatoes, costing only 14p and giving almost perfect roast potatoes in just over half an hour.
We cooked enough roast potatoes for two portions, but if you’re cooking for more people you may find yourself limited on space with the air fryer. Air fryers that we’ve tested have cooking capacities between 0.3kg and 2.2kg, so if you’re looking to buy an air fryer it’s important to choose a model that will allow you to cook as much food as you need.
The pressure cooker cooked the best roast potatoes and cost 23p less than the oven.
If you're roasting potatoes to go alongside a dish cooked on the hob, then the air fryer or pressure cooker are both quick, cheap choices. But remember that if your oven is on already, you might as well use it for your potatoes as well.
See which models come out top of our tests in our air fryer reviews and pressure cooker reviews.
Steamed vegetables: is the hob or microwave cheaper?
| Induction hob | Microwave | Pressure cooker | |
| Cooking time | 9 minutes | 5 minutes | 12 minutes |
| Energy used to cook | 0.19 kWh | 0.09 kWh | 0.2 kWh |
| Cost to cook | 7p | 3p | 7p |
| Saving (compared to hob) | N/A | 4p cheaper | Same price |
| Quality of cooking | 5 - perfectly steamed | 4 - a little firm for our tasters | 4.5 - slightly overcooked |
Our verdict: steamed vegetables
Cheapest appliance: microwave
There’s very little to choose between the three appliances we used to steam our broccoli. The induction hob gave the best results but the energy used was more than double the cost of using the microwave - 7p compared to 3p.
The pressure cooker used ever so slightly more energy than the induction hob and also overcooked the broccoli. The microwave and hob both give better control over the cooking time than a pressure cooker.
Switching to using a microwave for quick portions of cooked vegetables will save a little on energy costs each time, and this can add up over a year if you do it every day. We think it's worth giving a try.
Compare microwave specs to get the right model for you in our microwave reviews.
Our conclusion
While we found that you can make considerable energy savings with an air fryer and pressure cooker, bear in mind that if you don’t already have one of these smaller appliances it’s important to consider the initial outlay when looking at cost savings. For example, we’ve tested air fryers that cost anywhere between £30 and £300, and pressure cookers from £18 to £380.
So even though an air fryer might save you money compared to using an oven, it could be a long time before it pays for itself.
See all of our lab test results and compare costs with our air fryer reviews.
If you’re cooking lots of food at the same time, as is often the case on a Sunday afternoon, you’re better off using the oven rather than doing lots of batches with a smaller appliance such as an air fryer.
Our research explained
We chose the appliance models we used for our lab tests as they are typical mid-range examples of each type of appliance. When it comes to cooking ability, other models may perform better or worse than the ones we tested here.
To make our energy use calculations, we used the current average price of a unit of energy under the government's Energy Price Guarantee – 34p per kWh.
Find out more about how much your household appliances cost to run or head to our 10 ways to save on energy bills.
source https://www.which.co.uk/news/article/comparing-the-cheapest-ways-of-cooking-roast-dinner-aya512k6iz7x