According to Football Fanatics, a size 48 Nike football jersey fits a 51-inch chest. The back length of the jersey is 32.5 inches. A size 48 is considered an extra-large jersey.
Independent of size, professional football jerseys have changed significantly throughout the years. During the 1920s, jerseys were typically made out of heavy fabrics like wool. In the '30s, teams used basic colors but included identifying numbers on the shirts. During the next two decades, teams started to settle on recognizable team colors for the uniforms, though color changes often occurred. During the 21st century, the NFL permitted teams to wear alternate uniforms no more than three times during the season.