I got used Robeez for my almost 2 year old son approximately 5-6 months ago and he has been wearing them daily as house slippers. Today I noticed a hole on the sole, so I am trying to buy new ones. He's 2 years old now and wears shoe size 7. I'll be buying size 18-24 mos as that's what we have now and fits very well, in fact, has some space left. I have not noticed them being too tight as some of the reviews mention. Our son is tall, and rather slim, though. It's worth buying them!