Better Cybercrime Metrics Act This bill establishes various requirements to improve the collection of data related to cybercrime and cyber-enabled crime (cybercrime). Among the requirements the Department of Justice (DOJ) must enter into an agreement with the National Academy of Sciences to develop a taxonomy for categorizing different types of cybercrime faced by individuals and businesses; DOJ must establish a category in the National Incident-Based Reporting System for collecting cybercrime reports from federal, state, and local officials; DOJ's Bureau of Justice Statistics and the Bureau of the Census must include questions about cybercrime in the annual National Crime Victimization Survey; and the Government Accountability Office must assess the effectiveness of reporting mechanisms for cybercrime and disparities in reporting cybercrime data and other types of crime data.