This paper introduces a method for evaluating electrical fields in Reverberation Chambers (RCs) using the Chi distribution. The approach is particularly useful for estimating the Lowest Usable Frequency (LUF) of a given RC and its configuration. The LUF estimate includes the effects of correlation between electric field components, isotropic properties, and homogeneity by comparing measured values to theoretical predictions from the Chi distribution. An expected limit is also proposed to determine whether the RC demonstrates sufficient homogeneity, isotropy, and uncorrelated field components, or if the stirring process needs improvement. The method is applied to estimate the LUF of two different RCs.