The use of algebraic formulation for the solution of electromagnetic fields is becoming more and more widespread. This paper presents the theoretical development of two algebraic formulations of the magneto-static problem and their implementation in a three dimensional computational procedure based on an unstructured tetrahedral mesh. A complete description of the variables used and of the solution algorithm is provided together with a discussion about the performances of the method. The performances of the two procedures are tested and assessed versus cases with known solutions. Copyright (C) 2004 John Wiley Sons, Ltd.