This work numerically evaluates the possibility of using electromagnetic (EM) measurements to diagnose and quantify hydraulic fractures that are artificially generated in a horizontal well. Hydrofractures are modeled as thin disks that are possibly non-perpendicular to the well, and are filled with either sand-based or electrically-conductive proppant. The study quantifies the sensitivity of resistivity measurements to the presence, thickness, length, and dip angle (with respect to the well) of a hydrofracture. Numerical results indicate that low-frequency measurements performed with toroids and large-spacing between transmitters and receivers (60 feet) are adequate to characterize hydrofractures in openhole wells, while conventional low-frequency, short-spaced through-casing measurements are suitable for hydrofracture characterization in steel-cased wells.