The calculated distance (air line) between Le Havre and Trouville-sur-Mer is approximately 9 miles respectively 14 kilometers.
By car or train, the actual journey to Trouville-sur-Mer is certainly longer, as only the direct route (as the crow flies) between Le Havre and Trouville-sur-Mer has been calculated here.
Air line (approximately)
14 kilometers
8 nautical miles