Ecologists are faced with an over-abundance of ways to measure biodiversity. In this paper, I provide a compilation of and guide through this ticket of diversity metrics. I present a typology for diversity metrics that encompasses the three commonly considered categories of information: abundance, phylogenetic relationships, and traits (i.e., function). I update and expand previous summaries of diversity metrics. The formulas of those 117 metrics are presented in a standard notation and format that makes it easy to see the mathematical similarities and differences among the metrics. Finally, I propose a standard set of symbols for many of the metrics that makes their properties immediately obvious. This compilation will make it easier for researchers to identify the metric(s) most suited to their needs and will help guide future metric development.