The calculated distance (air line) between Saint-Germain-en-Laye and Vernouillet is approximately 7 miles respectively 12 kilometers.
By car or train, the actual journey to Vernouillet is certainly longer, as only the direct route (as the crow flies) between Saint-Germain-en-Laye and Vernouillet has been calculated here.
Air line (approximately)
12 kilometers
6 nautical miles