Predicting how soils respond to varying environmental conditions or land-use change is essential if we aim to promote sustainable management practices and help mitigate climate change. Here, we present a new ecosystem-scale soil model (MEMS v1) that is built upon recent, novel findings and can be run using very few inputs. The model accurately predicted soil carbon stocks for more than 8000 sites across Europe, ranging from cold, wet forests in sandy soils to hot, dry grasslands in clays.