Expressions for the electrical conductivity &sgr; and the isothermal Hall coefficientAHare transcendental equations in terms of film thickness and are solved graphically for film thickness. Measurements on vacuum‐deposited gold films in the thickness range 150–500 Å are compared with thickness measurements based upon the multiple beam interferometer methods of Tolansky and upon thickness calculations from microgram weighings. The deviations in measured film thickness are relatively constant, having a value of 30 Å for films greater than 300 Å. This constant deviation can be eliminated if the electron mean free path in bulk material is 370 Å in place of the value given in the literature (410 Å).