A rotor (20) for a compressor, in particular in a gas turbine, has a number of rotor blades (25) which are arranged around the rotation axis of the rotor (20) in the form of a rim and are each held in a circumferential recess (21) on the rotor (20) by a blade root (26), with the blade root (26) having a widening lower part (27) which engages behind two shoulders (24) that are formed on the side walls of the recess (21). In such a rotor, the life is lengthened in that the recess depth (T) of the recess (21) is substantially greater than a minimum recess depth (Tmin) which results in the rotor (20) having sufficient strength in the area of the blade attachment for starting, based on the predetermined material characteristics of the rotor (20) and the operating conditions of the compressor.