The calculated distance (air line) between Rambouillet and Paris 15 Vaugirard is approximately 25 miles respectively 41 kilometers.
By car or train, the actual journey to Paris 15 Vaugirard is certainly longer, as only the direct route (as the crow flies) between Rambouillet and Paris 15 Vaugirard has been calculated here.
Air line (approximately)
41 kilometers
22 nautical miles