A method for determining a propped fracture's (28) height (32) and width (30) wherein acoustic logging devices are used in a borehole. Compressional and shear wave velocities obtained by transmitting acoustic energy through the borehole (12) and into the formation are made at a plurality of locations before and after fracturing the formation. In-situ stresses are determined at the plurality of locations before and after fracturing the formation from velocities of the compressional and shear waves which were detecte before and after fracturing the formation. Differences between in-situ stresses obtained at each of said locations before and after fracturing the formation are used to predict a height and width of a propped fracture.