The calculated distance (air line) between Dayr Abū Ḑa‘īf and Khān Yūnis is approximately 99 miles respectively 159 kilometers.
By car or train, the actual journey to Khān Yūnis is certainly longer, as only the direct route (as the crow flies) between Dayr Abū Ḑa‘īf and Khān Yūnis has been calculated here.
Air line (approximately)
159 kilometers
86 nautical miles