We have obtained both virial and dynamical masses of a sample oflocal star forming galaxies from the UCM survey. The rotational curvesmeasured using the kinematics of the ionized gas where used as tracersof the mass of the system. The goal is to obtain a relationship with fotometric stellar masses,calculated from population synthesis models, in order to be used tomassive spectroscopy of large samples of star-forming galaxies atdifferent redshifts. The dynamical masses of the galaxies studied in this work areconsistent with the stellar masses estimated by Pérez-González et al.(2003). In this sense, the Hα emission line rotation curve isrepresentative enough of the real galaxy rotation curve (i.e.gravitational potential) for active star-forming galaxies. We have found that in the case of disk systems, the dynamical massesobtained are systematically smaller than virial masses, but there isno evidence of a simple relationship. This result can be understood ifgalaxies have a nuclear stellar formation burst that, in most cases,could dominate the velocity dispersions obtained from the spectra.However, we find a relationship between virial and stellar masses. Amore representative sample would provide a calibration good enough tobe used for future galaxies surveys.