The magnetic anisotropy of the cyclic octanuclear Fe(m) cluster [Cs subset of Fe-8{N(CH2CH2O)(3)}(8)]Cl was investigated. Based on a spin Hamiltonian formalism and the consequent use of all symmetries, the magnetic;anisotropy could be calculated exactly to first order, i.e., in the strong exchange limit; Experimentally, the magnetic anisotropy was investigated by magnetic susceptibility and high-field torque magnetometry of single crystals. The field and angle dependence of the torque at 1.7 K could be accurately reproduced by the calculations with one single parameter set, providing accurate results for the coupling constant and single-ion zero-field-splitting. These magnetic parameters are compared to those of several related hexanuclear ferric wheels and are discussed with respect to magneto-structural correlations for both coupling constant and single-ion anisotropy.