  Mass determinations are difficult to obtain and still frequently
characterised by deceptively large uncertainties. We review below the various
mass estimators used for star clusters of all ages and luminosities. We
highlight a few recent results related to (i) very massive old star clusters,
(ii) the differences and similarities between star clusters and cores of dwarf
elliptical galaxies, and (iii) the possible strong biases on mass determination
induced by tidal effects.
