I have Jordan 1 and 3 and they are US9,5. Jordan 1 are roomy but my BC3 feels a bit snug for some reason. Idk why on regular AF1 low size 9 feels good. I could go 9,5 on AF1s too I think.
I don't have a chance to try them on in store so I have to order blind.
I think the safest size for me...