The effect of soft impingement is modelled for the isothermal, diffusion-controlled growth of spherical precipitates in the solid-state. A two-stage soft impingement phase, isotropic growth in 3D and site saturation are assumed, which lead to a mean field approach for soft impingement. A mass balance is used in combination with a non-linear concentration profile approximation, instead of the ordinary linear concentration profile, to improve the description of growth under conditions of overlapping diffusion fields and low supersaturation. In addition, the capillary effects, dislocation assisted growth via pipe diffusion, and boundary assisted growth via boundary diffusion are discussed. The model has been applied to the growth of TiC-precipitates during tempering of a quenched Fe-C-Mn-Ti steel. The results are in good agreement with published experimental data of precipitate growth.