The calculated distance (air line) between Frankfurt am Main and Františkovy Lázně is approximately 162 miles respectively 261 kilometers.
By car or train, the actual journey to Františkovy Lázně is certainly longer, as only the direct route (as the crow flies) between Frankfurt am Main and Františkovy Lázně has been calculated here.
Air line (approximately)
261 kilometers
141 nautical miles