The calculated distance (air line) between Baytūnyā and Khān Yūnis is approximately 64 miles respectively 103 kilometers.
By car or train, the actual journey to Khān Yūnis is certainly longer, as only the direct route (as the crow flies) between Baytūnyā and Khān Yūnis has been calculated here.
Air line (approximately)
103 kilometers
55 nautical miles