The calculated distance (air line) between Dayr Abū Ḑa‘īf and Nablus is approximately 17 miles respectively 28 kilometers.
By car or train, the actual journey to Nablus is certainly longer, as only the direct route (as the crow flies) between Dayr Abū Ḑa‘īf and Nablus has been calculated here.
Air line (approximately)
28 kilometers
15 nautical miles