Not sure how big an air fryer to buy? Pick what you cook, say how many people are eating and see the basket size that fits, with a rough number of batches for each size.
The guide shows where its numbers come from (public portion guidance and published capacity figures), says where they are only rough estimates, and keeps the air fryer in perspective: the size changes how easily you cook, not what the food is.
Air fryer listings talk about litres, but nobody tells you what a litre feeds. Pick too small and you cook dinner in three rounds, with the first batch going cold. Pick too big and you pay for counter space you never use. The honest answer depends on two things: how many people you cook for and what you cook.
An air fryer works by blowing hot air around food. That only crisps things well when the air can reach every side, so the basket should be loaded loosely, not packed. Capacity therefore means how much food fits while still cooking evenly, which is less than the number of litres suggests.
Choose the basket for the dinner you cook most often, not the biggest meal you cook twice a year.
The grams per person are starting points, not rules. A portion of vegetables is 80 g for an adult according to the NHS 5 A Day guidance, so the slider starts at two portions' worth. The British Dietetic Association's portion sizes fact sheet gives about 140 g for a cooked fillet of white fish and 60–90 g for cooked meat. Raw chicken loses water as it cooks, so we start higher. The BDA sheet gives no weight for potatoes or chips, so our 200 g is a plain estimate. Move the slider to match your own plate.
The grams per litre are a rough rule from the capacity and load figures that makers and shops publish. Those figures do not agree with each other, which is why this tool shows a range of sizes and not one magic answer. A smaller basket can still do the job if you cook in two rounds.
An air fryer cooks with much less oil than deep frying, but the calories in your food stay the same; only the added oil changes. Cook meat and fish until they are cooked through, and check the middle of thick pieces rather than trusting the timer. A bigger basket makes it easier to overload, and a crowded basket cooks unevenly.
This guide only helps you choose a size. It is not advice about what you should eat. If you have a medical condition, are pregnant or breastfeeding, have or had an eating disorder, or take medication, talk to a doctor or dietitian before changing how you eat.
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A 4.2 L basket suits one or two people cooking one dish at a time, which is where the size guide lands for small households. Its parts go in the dishwasher.
A 7.2 L basket covers most of the family-size dinners in the size guide in one round, without needing two drawers.
Two stacked drawers let you cook a main and a side at once, which the guide says helps most for households of three or more.
