The calculated distance (air line) between Bourg-Saint-Andéol and Montpellier is approximately 65 miles respectively 105 kilometers.
By car or train, the actual journey to Montpellier is certainly longer, as only the direct route (as the crow flies) between Bourg-Saint-Andéol and Montpellier has been calculated here.
Air line (approximately)
105 kilometers
56 nautical miles