Passer rating (known as passing efficiency or pass efficiency in NCAA football) is a measure of the performance of quarterbacks or any other passers in American football and Canadian football. There are at least two formulae currently in use: one officially used by the National Football League and the Canadian Football League, and one used in college football. Passer rating is calculated using each quarterback's completion percentage, passing yardage, touchdowns and interceptions. A perfect passer rating in the NFL is 158.3. A perfect passing efficiency in college football is 1261.6.