In one or more embodiments, a system and method for filling a compress gas tank or fuel tank is provided, including determining a fill time (tfinal) predicted to produce a gas final temperature (Tfinal) based on one or more coefficients selected from a lookup table, mass average dispenser gas temperature for control (MATC), and alpha, determining a pressure ramp rate (RR), delivering gas to the compressed gas tank at a control pressure based on the pressure RR during a first portion of filling the compressed gas tank, determining a mass average enthalpy (MAE) and density, and delivering gas to the compressed gas tank at a target ending fueling pressure based on the density and the gas final temperature during a second portion of filling the compressed gas tank.