Mordekhai ben Eliezer Komtino (1402–1482) was a well-known scholar in the Judeo-Byzantine world—philosopher, exegete, mathematician, and astronomer. Among his works was Sefer ha-Ḥeshbon we-ha-middot. This paper deals with the geometrical part of that work. Although Euclid is sometimes quoted by the author, Komtino's geometry is not Euclidean. It comes from the field of metrological geometry ("practical geometry"). In addition to the famous Hebrew geometry composed by Abraham bar Ḥiyya in the twelfth century, Ḥibbur ha-meshiḥah we-ha-tishboret, Komtino also had before him a Greek manuscript containing the unique extant copy of Hero of Alexandria's Metrica (first or second century) and other metrological writings attributed to him.