The IPF uses the following age categories: sub-junior (18 and under), junior (19-23), open (24-39), masters 1 (40-49), masters 2 (50-59), masters 3 (60-69), masters 4 (70+). Age category is dependent on the year of the participant's birth. For example, if the participant turns 18 years old in January, he or she is still considered a Sub-junior until the end of that calendar year. Other federations typically break the Masters' categories down to 5-year increments, for example, 40–44, 45–49, 50–54, etc. Some federations also include a sub-master class from 33 (or 35) to 39.