Everyday experiences can evoke positive feelings that differ among individuals and guide their behavior. Although reward processing is often linked to positive feelings, few studies have assessed the mechanisms underlying subjective positive affect. Whether varied positive experiences share brain mechanisms that are predictive of subjective positive affect is unclear. Here, we used fMRI and predictive modeling to investigate how multiple dynamic, personalized positive experiences are encoded in the brain. Neural representations and functional integration of brain areas during experiences of monetary reward, social media, music, and positive autobiographical memories were used to predict participants' affect ratings of each experience. We found that, across experiences, positive affect was encoded in multivariate neural patterns and functional coupling of distributed cortical and subcortical brain areas, as well as some canonical value-linked brain regions, like the orbitofrontal cortex. We also found that more restricted sets of brain representations and functional connections linked to sensory processing were involved in encoding type-specific subjective positive affect. Our findings suggest that positive affect may be computed and communicated throughout the brain.