Tropical forest fragmentation results in habitat and biodiversity loss and carbon emissions. In this study, we quantified an increasing probability of tropical forest loss, including primary forest loss and loss of forests in protected areas, as fragments decrease in size. Large remaining forest fragments are located in the Amazon and Congo Basins and Insular Southeast Asia, with the majority of large extent/low loss fragments located in the Amazon. Tropical areas without large fragments, such as Central America, West Africa, and mainland Southeast Asia, have higher loss inside and outside of protected areas as land use pressures encroach on remaining natural forests. Results of this study may inform national to regional land use planning and forest restoration efforts.