didymos
baby slings come in 6 sizes. the length of cloth you need depends mainly on
the carrying method you chose.
apart from that your own size is of some importance. sizes 2 is used for the
"cradle" or "hip-carry" method, size 3 for the "rucksack",
size 4 for the "kangaroo-carry", size 5 for the "cross-carry"
and size 6 or 7 for the "wrap-cross-carry". in other words, if your
own body size is no more than 14 you can use sling size 6 for all carrying methods.
from body size 16 you are better off with sling size 7.
click below for detailed sizing information and an explanation
of the carrying positions