The following marks are the A and B qualification standards for the 2013 World Championships in Athletics. The standards have been changed from the 2011 standards. Each country may send a maximum of four athletes who have attained the A qualification mark in each specific event. A maximum of three athletes can compete in that event, with the sole exception of the relays, in which four of a possible six athletes may compete. In the case that no athlete of that nationality has achieved the A standard in an event, a country may send two athletes with the B qualification times, of which only one may compete at the Championships.