In the first part of this paper, we review some of the properties of the minimal polynomial of an element of a finite-dimensional power-associative algebra over an arbitrary field . Restricting attention to the case where is either or we briefly discuss r(a), the radius of an element a in which is the largest root in absolute value of the minimal polynomial of a. We then obtain a formula for the radius which is a variant of a well-known result in the context of complex Banach algebras. We prove that if f is a continuous subnorm on then for all We observe that while this formula holds for certain well-behaved discontinuous subnorms, it fails for others. The paper concludes with a study of the relations between stable subnorms and the above defined radius. For example, we show that if a stable subnorm f is continuous on then f is radially dominant, i.e., f(a)≥ r(a) for all .