Modeling the kinetics of calcite dissolution in neutral and alkaline solutions

•Kinetics of calcite dissolution is described from nanoscale to crystalline grains.•Model rates are consistent with step velocities and pit densities measured with AFM.•Grain dissolution rates with small spread agree with reanalysis of laboratory data.•Nanosized grains are in a different kinetic regime and dissolve much faster.•Activation energies are microscopically interpreted and agree with laboratory data.