How long does it take an American Staffordshire Terrier Mix to reach full size?

We have a 13 week old Staffordshire Terrier Mix who is 28 Lbs. He will probably get to 60lbs so how long does it take for him to reach his full size???we took him to the vet and they said he would be 60 or more....I just wasnt sure how long it would take for him to get that big since he is only 13 weeks i figured it wouldnt be to long....We got him from the humane society and they said he is a pitbull mix but doesnt say what else he is mixed with so that part we do not know

depends what he is mixed with as to how longitwill takehim toreach full size small dogs generally reach full size by one year old and larger dogs can take up to 18 months to befully grown

What's he mixed with?? If you can predict that he will reach 60 lbs... ?? How come you don't know when he'll get there?? If he is 28 lbs at 13 weeks of age, he is going to be bigger than 60lbs when he is an adult..

larger breeds can take more then 2 years to be fully grown

Most likely to reach his full height( at the shoulders) by approx 9-10 months but he'll fill out more after that muscle wise. Most pits I've seen are pretty much full groen by 1 year.