In recent years it has been well documented that the bubble surface area flux plays a fundamental role in the performance of industrial flotation machines. Modern instrumentation is not yet capable of providing a robust direct measurement of this parameter, and the widespread industrial use of the available indirect methods have been hampered by the limitations of the available instruments and the complexity of the required calculations. This paper describes a reliable and maintenance-free method for online inference of bubble diameter and bubble surface area flux using CiDRA’s GH-100 gas holdup meter. A method is presented for coding the iterative drift-flux analysis calculations for column cell bubble diameter and surface area flux using standard expert system or DCS programming language. An alternative empirical method applicable to mechanical cells is also demonstrated. Operating data from an industrial plant historian is presented.