One goal of Designing for Human Variability (DfHV) is to optimize the interaction between user and device. Often, this interaction is dictated by the spatial dimensions or shape of the artifacts with which people interact. A novel approach that applies DfHV principles including virtual fitting trials to optimize the shape of an artifact is presented and applied to the design of a tool handle. By breaking the problem apart into discrete blocks, called the hand model and tool model, application of standard optimization techniques is facilitated. The benefits of the approach include the ability to consider handles with variable cross-sections and to systematically consider the effects of multiple sizes. The methodology presented here is configurable for any given population and may be applied to other DfHV design problems.