how old does a senator have to be

A person must be at least 30 years old to be eligible to serve as a U.S. senator. This age requirement is set by the U.S. Constitution to ensure senators have sufficient maturity and experience to perform their duties. In addition to age, a senator must have been a U.S. citizen for at least nine years and be an inhabitant of the state they are elected from at the time of the election.