In the world, วัยวุฒิ (วัยวุฒิ 
) is a rare principally masculine, but very seldom feminine forename. The first name วัยวุฒิ is habitual in South-eastern Asia, particularly Thailand, where it is a rare predominantly masculine, but very infrequently female name. Likewise, วัยวุฒิ is the last name as well as the forename.