The calculated distance (air line) between Eggenstein-Leopoldshafen and Mannheim is approximately 28 miles respectively 45 kilometers.
By car or train, the actual journey to Mannheim is certainly longer, as only the direct route (as the crow flies) between Eggenstein-Leopoldshafen and Mannheim has been calculated here.
Air line (approximately)
45 kilometers
24 nautical miles