The calculated distance (air line) between Samtse and Samdrup Jongkhar is approximately 148 miles respectively 239 kilometers.
By car or train, the actual journey to Samdrup Jongkhar is certainly longer, as only the direct route (as the crow flies) between Samtse and Samdrup Jongkhar has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles