A new method to determine the breakdown voltage of SiPMs is presented. It is based on a DC model which describes the breakdown phenomenon by distinct avalanche turn-on (V01) and turn-off (V10) voltages. It is shown that traditional DC methods relying on the analysis of reverse current-voltage curves measure a value either near V01 or between V01 and V10 while V10 results by complex gain-voltage measurements. The proposed method reveals how the microcell population distributes around V01. It is found that if this distribution is assumed to be normal, then both V01 and V10 of the SiPM can readily be extracted from current-voltage curves. Measurements are in good agreement with the theoretical model.