This simple guide should help you. All you need is a tape measure!
These are age rated on each product, look at the product details to see if they are suitable
These come in one size, 185mm x 490mm
For newborns, size 2, 3-6 months
One size for newborns
Not sure what size bib to go for?
The bandana bibs:
Neck size 30–35cm, drop from chin to point of the bib 17cm
The XL bibs:
Neck size 35–40cm, 21cm drop from chin to point of bib.
The XXL bibs:
Neck size 40–45cm, 23cm drop from chin to point of bib.