The calculated distance (air line) between Strasbourg and Châlons-en-Champagne is approximately 156 miles respectively 251 kilometers.
By car or train, the actual journey to Châlons-en-Champagne is certainly longer, as only the direct route (as the crow flies) between Strasbourg and Châlons-en-Champagne has been calculated here.
Air line (approximately)
251 kilometers
135 nautical miles