This collection contains five datasets related to the supposedly ancient legal maxim “iudex non calculat”. They are supplements to academic research reported by Hamann, Iudex Non Calculat: Exploring the Number-Aversion Maxim as an Intellectual Trans-Atlantic Export, German Law Journal 27 (2026), in print. This article explains the sources of, and analyses, the following data: Bundestag_1950-2024.csv: a comprehensive list of oral plenary debates in German parliament where congressmen mentioned non calculat, with additional metadata on each congressman Curt_Gruneberg_UMKC&FAU.zip: archival materials on the first known adopter of non calculat in English journals, being economics professor Curt Gruneberg (* 24 Dec 1895 Berlin ... † 14 Jan 1950 Kansas City), as provided by the University of Missouri-Kansas City and Friedrich Alexander University at Erlangen-Nuremberg JournalArticles_1947-2024.csv: a comprehensive list of scholarly articles from academic journals in English language that mentioned non calculat in their text, except in mere references SoSciSurveyDE_2023...*: the results (*.csv), codebook (*.xlsx) and questionnaire (*.pdf/.xml) of a survey among German law students which ran from 8 Aug to 8 Sep 2023 on the platform soscisurvey.de, asking for knowledge about and attitudes towards non calculat. Titelwort-calculat_1975-2024.csv: a comprehensive list of scholarly articles from law journals and Festschrifts in German language that mentioned non calculat in the respective article’s title. All time series are up to and including the year 2024. Data were last updated on 30 Sep 2025. Comma-separated value files (.csv) in this collection are UTF8-encoded.