Our garments are all true to size, but as we are not all the same shape and like different fits, it is best to measure to ensure you order the correct size!
Our tees are standard, unisex style. 
We suggest using your own, best fitting tee - lay it out nice & flat then measure from underarm to underarm. 
Again, with hoodies, measure your favourite from underarm to underarm. 
If you don't have a garment to measure, just measure across your chest.
Sizing is the same for US as the baby range is in age of months. As for all items, you are best measuring and comparing against the size guide.
Still unsure of which size to get? You can drop us a message and we can give you some help.