The calculated distance (air line) between Reims and Crépy-en-Valois is approximately 51 miles respectively 83 kilometers.
By car or train, the actual journey to Crépy-en-Valois is certainly longer, as only the direct route (as the crow flies) between Reims and Crépy-en-Valois has been calculated here.
Air line (approximately)
83 kilometers
45 nautical miles