This dataset consists of Particle Size Distribution (PSD) measurements made on 419 archived topsoil samples and derived aggregate stability metrics from arable and grassland habitats across Great Britain in 2007. Laser granulometry was used to measure PSD of 1–2 mm aggregates before and after sonication and the difference in their Mean Weight Diameter (MWD) used to indicate aggregate stability. The samples were collected as part of the Countryside Survey monitoring programme, a unique study or ‘audit’ of the natural resources of the UK’s countryside. The analyses were conducted as part of study aiming to quantify how soil quality indicators change across a gradient of agricultural land management and to identify conditions that determine the ability of different soils to resist and recover from perturbations.