Cognitive decline often accompanies natural aging, which results in younger adults outperforming older adults, on average, on tasks requiring attention, memory, or mental flexibility skills. This performance gap between age groups persists even after people train on these tasks, but it remains unclear whether the gap persists when individuals, rather than groups, are compared at different training levels. In this paper, we analyzed 9,923 users between 18-90 years old (63% over 60) who performed a variety of cognitive tasks on an online cognitive training platform. We quantified an older adult’s potential to catch up to, or perform as well as, a younger adult. We found that the probability of catching up to someone decades younger increases with differential amounts of training on a variety of cognitive tasks. These findings suggest that age-related performance deficits can be overcome with additional training.