The calculated distance (air line) between Frankfurt am Main and Steinbach am Taunus is approximately 6 miles respectively 10 kilometers.
By car or train, the actual journey to Steinbach am Taunus is certainly longer, as only the direct route (as the crow flies) between Frankfurt am Main and Steinbach am Taunus has been calculated here.
Air line (approximately)
10 kilometers
5 nautical miles