Objectives <p>Review and assess the primary metrics used in the crime and place literature to measure concentrations of crime, discussing their utility and limitations. We also propose a new metric that meets the criterion of Ockham’s razor, and is based on the 50-X metric proposed by Weisburd (2015) in identifying the law of crime concentration—the percentage of street segments that account for 50% of crime.</p> Methods <p>Calculations of metrics using simulations, theoretical examples, and empirical examples are used to compare 7 different metrics of crime concentration: our new metric, the 50-X metric, the 5-X metric (Hipp and Kim 2017), the adjusted 50-X metric (Andresen and Malleson 2011), the Generalized Gini coefficient and the standard Gini coefficient (Bernasco and Steenbeek 2017), and the marginal crime concentration metric (Chalfin et al. 2021).</p> Results <p>We show that different metrics can provide very different information regarding crime concentrations, and some of these metrics are quite sensitive to sample size issues, computational complexity, and interpretability. A new metric, the generalized 50-X measure, is developed that addresses the issue of small Ns of crimes relative to streets, and that is easy to compute and interpret.</p> Conclusions <p>The utility of different measures of concentrations relates both to the principle of Ockham’s razor, and to the specific goals of the metric. We argue that the generalized 50-X measure is consistent with policy interest in hot spots of crime, and that it adheres to the principle of Ockham’s razor.</p>