Disadvantages

1. The value of mode cannot always be determined. In some cases we may have a bimodal series.
2. It is not capable of algebraic manipulations. For example, from the modes of two sets of data we cannot calculate the overall mode of the combined data. Similarly, the modal wage times the number of workers will not give the total payroll except, of course, when the distribution is normal and then the mean, median and mode are all equal.
3. The value of mode is not based on each and every item of the series.
4. It is not a rigidly defined measure. There are several formulae for calculating the mode, all of which usually give somewhat different answers. In fact, mode is the most unstable average and its value is difficult to determine.
5. While dealing with quantitative data, the disadvantages of the mode outweigh its good features and hence it is seldom used.