In a radically new approach to morphological typology, Stump and Finkel define an inflection-class system’s complexity as the extent to which it inhibits motivated inferences about its paradigms’ word forms. They demonstrate that a number of independent factors contribute to such complexity, which is therefore subject to different kinds of measurement. Drawing on evidence from a diverse range of languages (including Chinantec, Dakota, French, Fur, Icelandic, Ngiti and Sanskrit), the authors propose ten measures of an inflection-class system’s multifaceted complexity. Some measures involve principal parts (a conceptual refinement of the notion from language pedagogy); others are sensitive to the full network of implicative relations uniting a paradigm’s cells. The authors explain their implementation of these measures; their computational tool and the data they analyze are both freely available online. This investigation reveals that the implicative structure of inflectional paradigms is a domain of considerable variation, both within and across languages.