The calculated distance (air line) between Saint-Brice-sous-Forêt and Le Mans is approximately 120 miles respectively 194 kilometers.
By car or train, the actual journey to Le Mans is certainly longer, as only the direct route (as the crow flies) between Saint-Brice-sous-Forêt and Le Mans has been calculated here.
Air line (approximately)
194 kilometers
104 nautical miles