The authors agree that the surname derives from the trade name calzolaro (shoemaker), being semantically equivalent to surnames such as Callegari, Scarparo and others of the same lexical family.

E. Rossoni adds a complementary interpretation: the surname would not derive directly from the trade itself, but from the medieval guilds of craftsmen, as also happens with surnames such as Fabbri or Speziali. In that sense, it would be no coincidence that the surname is concentrated in cities where there were old trade guilds.

As for the geographical distribution, E. De Felice notes that the surname is spread in northern Italy, with high frequency in Emilia, and in the centre, especially in Tuscany, where the specific variant Calzolai exists. Rossoni specifies that the form Calzolari is concentrated in the Reggio Emilia, Modena, Bologna and Ferrara areas, while the variant Calzolaro appears in the southwestern area of Lecce, in the region of Puglia.