On https://biogeo.ucdavis.edu/data/gadm3.6/gadm36_shp.zip you can download administrative areas for the whole world. Each country has several administrative subdivisions (gadm36_0 - gadm36_5), where gadm36_0 is country level and gadm36_1 is state level. I am working with gadm36_2 data (which corresponds to counties in the U.S. e.g.). I was wondering whether there were area (administrative unit) sizes (in square kilometers) for the whole dataset available? One could calculate them using GIS-programmes. Though, doing so is tedious as you basically have to change your projection (CRS) for every local calculation.