[3][1] Following the end of the war, he enrolled at the University of Tartu in 1920; graduating with a master's degree in chemistry in 1925 with the thesis Investigation of Alkyl Carbonate Constants.

[2][4] In 1926 he relocated to France as a scholarship holder and received his Doctor of Science degree from the University of Paris in 1929 following the publication of his thesis Contribution to the Development of Complexes of Oxalics and Carbonics in Trivalent Cobalt by Masson publishing house.

[7] In 1936, he worked as a chemist of the State Oil Shale Industry Laboratory and concurrently as a teacher at the Virumaa Mining School in Jõhvi.

[1] Fluent in several languages, Jaan Kalviste translated mathematician Henri Poincaré's 1902 book Science and Hypothesis from French into Estonian (Teadus ja hüpotees) in 1936.

[8] On 15 June 1936, Jaan Kalviste was part of a group of approximately ten chemists at a seminar organized at the laboratory of the Männiku military ammunition stores in the Tallinn district of Nõmme when a massive explosion occurred, destroying the entire site and starting a blaze in the nearby heath and pine forest.