Strategies to promote plug-in electric vehicle (PEV) adoption include consumer education about potential energy cost savings. However, the complexity of comparing gasoline and electricity prices makes it difficult to quantify. Vehicle energy cost calculators help consumers navigate this complexity, and research shows they can increase consumer knowledge and positive attitudes about PEVs. At least nine of these calculators exist, but none appear to be based on behavioral research. They vary in terms of a number of features that are potentially important for user experience, education, and persuasion. This seed funding will support development of design specifications for vehicle energy cost calculators based on behavioral research. The researchers will draw implications for vehicle energy cost calculator design from literature on consumer perceptions of energy costs, fuel economy, and electric vehicle adoption. They will also conduct comparative usability testing with several existing vehicle energy cost calculators. The research team will disseminate findings to a range of stakeholders to encourage development and applications of vehicle energy cost calculators that facilitate PEV adoption.