The calculated distance (air line) between Khān Shaykhūn and Al Bāb is approximately 80 miles respectively 129 kilometers.
By car or train, the actual journey to Al Bāb is certainly longer, as only the direct route (as the crow flies) between Khān Shaykhūn and Al Bāb has been calculated here.
Air line (approximately)
129 kilometers
70 nautical miles