Total-energy band calculations are used to analyze the magnetic phases of metallic elements as functions of volume. The calculations utilize a fixed-spin-moment procedure, which is described and justified as a natural generalization of density-functional theory. This procedure finds the ground-state energies of electronic systems under two constraints, and hence determines the system energy as a function of two variables - volume and magnetic moment. The energy function is used to find the ferromagnetic phases and their ground-state properties, including bulk moduli and magnetic susceptibilities. The systems studied are fcc Fe, fcc Co, bcc Ni, fcc Pd, and bcc Mn, each of which undergoes a phase transition for small changes of the lattice constant from equilibrium (zero-pressure) values.