Method for controlling the metered amount of detergent in an automatic washing machine or the like

In a clothes washing machine that comprises a washing tub (4) containing a drum (5), and is adapted to carry out a washing and rinse cycle followed by respective water discharge phases, the method calls for: during each water discharge phase, the time intervals (Tw, Tr) to be measured, which elapse from the instant in which the water in the tub (4) lowers down to a first level (L2), to the instant in which the water further decreases down to a level (L1); and when the ratio (R) between the so measured time intervals (Tw, Tr) is detected to be higher than a given threshold value (Rx), an alarm signal to be generated which is indicative of an excessively metered amount of detergent.