The shirt is exactly the same as I bought in the cub shop a few years ago for my older son. I bought 28 as my almost 8 year old in very skinny (though average height) and it is still a generous size - I would expect to get a year out of it at least and the next size would be huge. The inside is soft and fluffy and the material thick so as to make a warm sweatshirt great for outdoor wear.
This is a very good quality sweatshirt - and should last a fair while. The only downside is that the sleeves are about 3" too long. This fits an 8 year old - average size. Pleased with the product overall though.