| Year of Birth | Age Group |
| 2015 | U8 |
| 2014 | U9 |
| 2013 | U10 |
| 2012 | U11 |
| 2011 | U12 |
| 2010 | U13 |
| 2009 | U14 |
| 2008 | U15 |
| 2007 | U16 |
| 2006 | U17 |
| 2005 | U18 |
| 2004 | U19 |
Example
If you were born in 2015 and are 7 this year or going seven before or on 31st Dec 2022 you are Under 8.
You can also run in one age group older, i.e. an athlete born in 2012 can run in an U11 race (in age) but also in an U12 race (out of age).
Events
- Mayo XC
- Connacht XC Championships
- National School XC
Mayo XC
The Mayo XC is divided into Mayo XC evens and Mayo XC unevens.
The Evens are for the even age groups;
- U8
- U10
- U12
- U14
- U16
- U18 & seniors
The Unevens are for the odd age groups;
- U9
- U11
- U13
- U15
- U17
- U19 & seniors
The Mayo XC races are not qualifiers for the Connacht XC Championships.
Connacht XC Championships
The Connacht XC Championships are also divided into evens and unevens age group race categories.
The Connacht races are qualifiers for the all-Irelands which begin at U11.
The youngest an athlete can participate in Connachts would be U10, where they race one age group older.
National School XC
Each September, there are National School XC races.
These races do not use the standard age categories. There are 2 race categories, based on what school class the athlete is in.
- 3rd & 4th Class
- 5th & 6th Class
