The calculated distance (air line) between Al Bīrah and Khān Yūnis is approximately 66 miles respectively 107 kilometers.
By car or train, the actual journey to Khān Yūnis is certainly longer, as only the direct route (as the crow flies) between Al Bīrah and Khān Yūnis has been calculated here.
Air line (approximately)
107 kilometers
58 nautical miles