The particle breakage of angular and porous calcareous sands at high strain rates (HSRs) is important but rarely quantified. This paper conducts a series of split-Hopkinson pressure bar (SHPB) tests to investigate the particle breakage of calcareous sand at different impact energies, relative densities, moisture contents and particle gradations. The stress-strain relationships of calcareous sand under impact loading are nearly linear, indicating that particle breakage and restructuration occurs during the entire loading period. The particle breakage of calcareous sand increases exponentially with impact energy, determining the parameters describing the crushability. Particle breakage first decreases with the water content and subsequently increases. For partially saturated specimen, more coarse-sized particles are crushed than coarse-sized particles in dry and unsaturated moist specimens, but fewer fine-sized particles are crushed compared with the fine-sized particles in dry and unsaturated moist specimens. Semi-empirical evaluations are supplied to estimate the particle breakage of sand at HSRs. (C) 2020 Published by Elsevier B.V.