While each individual child's readiness to play a team sport such as football may vary by age, most kids are ready to play football by age 6 or 7. This is the age where most children not only have sufficient physical capabilities to engage in team sports but also have enough social development to understand rules, sharing and other social aspects of team sports. However, there is an argument against children under the age of 14 engaging in tackle football due to the risk of brain injury such as concussion.
The Pop Warner junior football league has tackle football teams in age divisions for children as young as 5 and as light as 35 pounds. However, the fact that the sport is available for play does not necessarily mean that it is safe. In 2013, two Pop Warner coaches in Massachusetts were suspended after five players, all of whom were about 10 years old, suffered from head injuries during a single game. It may be up to the parent to determine whether such a risk is worth it. The successful pro quarterback Tom Brady was not allowed to play tackle football until he was a teenager, a fact that likely had no negative impact on his successful professional career.