In this paper, we have established a protocol to estimate the precision of BLS spectrometers from the standard deviation of repeated measurements in pure water. This study showed that, regardless of the technology of the spectrometer, the precision only depends on the SNR. We have also evaluated the accuracy, for both the frequency shift and the linewidth, from the difference between theory and measurements in saline solutions of increasing concentrations. Our analysis shows that only the acquisition time and laser power required to reach a given SNR should be quoted. This protocol is easy to replicate and can be used across different labs to evaluate the performances of different optical designs.