In this paper, methods for finding the demagnetization factor, specifically for permanent magnets, are considered and compared. Widely applied and cited literature expressions are compared to high resolution numerical modeling in order to establish the applicability of the expressions. Overall, the expressions are found to be very closely correlated with the modeling results. In the second part, a simple geometrically based method to find the demagnetization factor is proposed and compared to the numerical modeling results. Fairly good correspondence is found, indicating the applicability of this simple method.