One example of well treatment design based on three-dimensional wellbore shape can be implemented as a computer-implemented method. Wellbore data including acoustic logging data that defines an internal shape of a wall of the wellbore at multiple locations around the perimeter of the wellbore can be received. A volume of an open hole portion of the wellbore that includes the multiple locations can be determined using the wellbore data. Using the volume of the open hole portion of the wellbore, a volume of a fluid loss treatment to treat the portion of the wellbore for well fluid loss can be determined.