Nearly every glacier in Greenland has thinned or retreated over the past few decades, leading to accelerated glacier advance, increased rates of sea level rise, and global climate impacts. To understand how calving retreat has affected the ice mass balance in Greenland, we combine 236,328 manually derived and AI-derived observations of glacier end positions collected from 1985 to 2022 to create a 120 m resolution mask that defines the ice sheet. every month for nearly four decades. Here we show that the Greenland Ice Sheet (GrIS) has lost 5,091 ± 72 km since 1985. ² area, corresponding to 1,034 ± 120 Gt of ice lost during retreat. Our results suggest that by neglecting pre-calving retreat, current consensus estimates of ice sheet mass balance underestimate recent mass loss from Greenland by as much as 20 %. The mass loss we report had minimal direct impact on global sea level, but is sufficient to influence ocean circulation and the distribution of thermal energy across the globe. (Chad A. Greene, Alex S. Gardner, Joshua K. Cuzzone)