The calculated distance (air line) between Az Zaytūnīyah and Nablus is approximately 19 miles respectively 31 kilometers.
By car or train, the actual journey to Nablus is certainly longer, as only the direct route (as the crow flies) between Az Zaytūnīyah and Nablus has been calculated here.
Air line (approximately)
31 kilometers
17 nautical miles