Social networks have become the primary way of communication and source of information. They are especially important for adolescents who use them to build and develop relationships, so Instagram is one of the most commonly used social networks. According to previous research, adolescents spend a lot of time on Instagram, so the question is what characteristics of students are associated with spending time on Instagram. Therefore, the aim of this research was to examine the contribution of subjective well-being and motives for using Instagram in explaining the intensity of using Instagram. Participants (N = 121) were seventh and eighth grade students from 12 primary schools in the City of Zagreb. The results showed that students who have a lower level of life satisfaction and a lower level of positive affect use Instagram to a greater extent for the motive of escapism, but not for fear of missing out. Those who have a higher level of negative affect, use Instagram to a greater extent both because of the motive for escape, but also because of the fear of missing out content on Instagram. There is no statistically significant correlation between subjective well-being and instrumental motives for using Instagram, except for the self-expression motive. Students with a higher level of negative emotions are more likely to use Instagram for self-presentation motives. All the motives for using Instagram are positively related to the emotional connection with Instagram. The daily time spent on Instagram is associated only with the instrumental motives of social interaction and enjoyment and relaxation. Significant positive predictors of emotional connection are all motives except escape, while the only significant predictor of the amount of daily time spent on Instagram is the motive of enjoyment and relaxation.