How Old is Ariana Grande? Full Popstar Video Click to: https://www.youtube.com/watch?v=Ja7SswKCyQM Can you GUESS THE AGE of a Celebrity? In the Quiz Popstar Episode we ask this question: How Old is Ariana Grande. Adulthood is usually divided into several periods: young or early adulthood (approximately aged 18–39), middle adulthood (40–59), and old age (60 ). Old age is typically divided into the periods of young old (60–75) and old old (75 and up). Subjective definitions of age are also importa