This mixed-methods study explores the efficacy of a multidimensional identity measurement tool that aims to represent the diverse language experiences of heritage language learners (HLLs) and heritage language speakers (HLSs). Drawing on the thematic commonalities across 13 definitions of HLLs, a questionnaire was developed to capture age of acquisition, self-reported proficiency level, home exposure, language maintenance efforts, and cultural and familial ties to the heritage community. Questionnaire data spanning HLSs (N = 135) of 41 heritage languages were submitted to K-means cluster analysis to investigate identity-based trends across respondents. Interviews (n = 10) and autobiographical essays (n = 4) from a subset of respondents from each resulting cluster were thematically analyzed and used to corroborate descriptive HLS profiles from cluster analysis results. Three HLS profiles emerged from the data set, and their defining characteristics (based on the five HLL identity themes) illustrate the complex interplay of language, culture, family, and education within the HLS population. Qualitative analysis of respondents' perspectives highlights the challenges of quantitatively measuring inherently qualitative experiences. The study concludes with implications for how questionnaire-based instruments derived from bottom-up statistical analyses can be leveraged in future research, advancing the agendas of linguists and educators to better understand and support HLSs.