A new relation is proposed for calculation of local magnitudes in Greece. For this purpose, there were used synthetic Wood-Anderson (SWA) recordings of 98 digital broad-band stations operating between 2007 and 2011. These stations are installed at the sites of the seismological networks of: a) the National Observatory of Athens(HL), b) the Department of Geophysics of the Aristotle University of Thessaloniki (HT), c) the Seismological Laboratory of the University of Athens (HA) and d) the Seismological Laboratory of the University of Patras (HP). All these institutions constitute the recently (2004) established Hellenic Unified Seismic Network (HUSN). These recordings are used to calculate a refined geometrical spreading factor and an anelastic attenuation coefficient, representative for Greece and surrounding area, proper for estimating local magnitudes in this region. Individual station corrections are also calculated in order to further ameliorate magnitude estimation accuracy. Comparison of such calculated local magnitudes with corresponding original moment magnitudes revealed that these two scales are equivalent for awide range of values (2.9≤MW≤6.4).