LOl, totally depends on the brand and the size of the baby and if you like to buy it a bit oversize !

Generally, I would say size zero for an 8 month old. But sons babies are big for their age and sizes vary so much, you just buy what fits your bub at the time

It also depends on the brands. Some are not the same as others. e.g. I bought 2 swimsuits for a baby girl, same brand too, but one pair was longer than the other. Prior to that I bought trackpants for girls with a two year age gap. The pair that was marked as being the larger size was actually shorter than what was supposed to be small. As they were sisters and the youngest one always tried to claim everything we cut the tag out of one pair and she was none the wiser. Armholes are smaller in some brands. The body might be the right size but you will struggle to get baby’s arm through the armholes and not be too tight when you succeed. If the clothes are a surprise and you don’t want to discuss it with the Mum first, may I suggest that you buy cotton or fabric that is mainly cotton as some babies get eczema from synthetic fabrics including polyester. I know several babies that the cause has been traced to that issue. It is beeter buy things a little large than it be skin tight and baby grow out of it within a month. So frustrating.

What ever fits! Generally speaking, going on Australian sizing guidelines, an 8 month old should be in size 0…… Maybe looking at size 1 in the not too distant future

yeah depends on the child but i agree with 0. maybe get him a blanket or something so you don’t have to worry about sizing or ask the parent

How much do you know about the baby tall, short, skinny, solid build.
Sometimes you have to haver one size larger than average if baby it tall or a little thicker set
e,g, one of ours needed one size bigger top than pants.

All depends on whether you have a big baby or not, would guess about size 0, the way I work it out “roughly” is:
0000/00000 – Newborn
000 – 0-3 months
00 – 3-6 months
0 – 6-12 months
1 – 12 months +
That is roughly what I did for my girls but every child is different and with my 2nd daughter she was small so I used them a lot more within each month

Your best bet would probably be a 0. Obviously depends if he is big or small for his age. Also, consider length/height – you may want to size up or down.