The calculated distance (air line) between Saint-Amand-les-Eaux and Le Havre is approximately 162 miles respectively 260 kilometers.
By car or train, the actual journey to Le Havre is certainly longer, as only the direct route (as the crow flies) between Saint-Amand-les-Eaux and Le Havre has been calculated here.
Air line (approximately)
260 kilometers
140 nautical miles