Quantification of Terfenol-D material properties is not readily achieved through standard stress-strain test procedures due to the sensitivity of material properties to changes in magnetic and mechanical loads. A Terfenol-D transducer can be used to measure material properties under varied operating conditions. The development of the measurement and calculation procedures used to obtain material properties is based on the model of low signal, linear magnetostriction, linear transduction equations for a transducer, and a one degree of freedom mechanical model of the transducer. Vector impedance and admittance analysis is used to determine the transducer resonant, anti-resonant, and half power point frequencies. Using these frequencies, acceleration from an accelerometer mounted on the transducer, readily measurable transducer and Terfenol-D rod parameters (mass, length, etc.), and the calculation procedures described, pertinent material properties such as the Young's moduli, permeabilities, magnetomechanical coupling factor, and the linear coupling coefficient (d33) can be determined. The subtleties of applying this theory to real world non-linear Terfenol-D operated in a transducer are addressed, including proper design and operation of a transducer to achieve circular Nyquist mobility loops. Experimental results from this method are compared with other research and the material property trends are found to be consistent.