The calculated distance (air line) between La Chapelle-sur-Erdre and Le Havre is approximately 170 miles respectively 273 kilometers.
By car or train, the actual journey to Le Havre is certainly longer, as only the direct route (as the crow flies) between La Chapelle-sur-Erdre and Le Havre has been calculated here.
Air line (approximately)
273 kilometers
147 nautical miles