AccretR calculates mass, radius, and bulk composition along a specified growth track for orderly/hierarchical, runaway, and random particle accretion models. Elements in the model include concentrations of H, C, N, O, Na, Mg, Al, Si, S, Cl, K, Ca, and Fe. Maximal water is also computed, assuming all H goes into forming water. Accretional heat is also calculated. AccretR is optimized to build Jupiter's moon Europa, and Saturn's moons Titan and Enceladus, from CI, CM, CR, CK, CO and CV carbonaceous chondrite meteorites, cometary material (using comet 67P/Churyumov-Gerasimenko), and pure water ice.