The present invention is directed to simulating evaporation of a droplet of a fluid, and may be embodied in a system, method or a computer-readable medium encoded with instructions for a processor to carry out such simulation. The present invention solves equations, which may represent an approximation of evaporation of the droplet on a domain whose size is varying over time. The boundaries of saturation regions are tracked and updated over time, and the equations are iteratively solved with the new boundaries of the saturation regions.