Calculating How Much Food To Buy
The quantity you need depends largely on the cut you’re using and the way you cook it. You’ll need less, for example, for a dish with a rich sauce, and more for a plain roast. As a rough guide, estimate about 100-175g (4-6oz) per portion for boneless cuts, and 175-350g (6-12oz) for meat on the bone.
Allow about 225-350g (8-12oz) of chicken or turkey per person and you won’t go far wrong. Duck and goose have much more fat, so make it about 700-900g (1-1/2 – 2lb) when you’re serving these.
Fish and shellfish
Allow about 175g (6oz) fish on the bone per serving; and for filleted fish, about 100g (4oz). Whole fish weighed with head and bones will feed two to three per 450g (11b). Shellfish is richer so allow slightly less: for easy calculating, assume that crabs and lobsters will yield about half their weight in meat.
Pasta and rice
Calculate about 50g (2oz) per person for an accompaniment or side dish; but double the quantity if pasta or rice is the main part of a dish – a risotto or pasta main course, for example.