How Big Does A Pitbull/mastiff Mix Get?

No way to say or predict or an average with a mixed breed like there is with the breeds. Pups could take any traits or combination of traits from both (or more) breeds. Even pups from one litter could all be completely different from each other. They are pretty different. One is a smaller to medium size (provided there aren't other breeds there too) and one is a giant breed and on and on. You can search petfinder for same or similar mixes and also would have to study both breeds (looks, traits, character, personality, health problems ect.) to get an idea of all the possibilities.
www.amstaff.org www.ukcdogs.com www.mastiff.org www.petfinder.com
www.dogfoodanalysis.com