The calculated distance (air line) between Frenštát pod Radhoštěm and Karviná is approximately 26 miles respectively 41 kilometers.
By car or train, the actual journey to Karviná is certainly longer, as only the direct route (as the crow flies) between Frenštát pod Radhoštěm and Karviná has been calculated here.
Air line (approximately)
41 kilometers
22 nautical miles