The calculated distance (air line) between Jisr ash Shughūr and Manbij is approximately 104 miles respectively 167 kilometers.
By car or train, the actual journey to Manbij is certainly longer, as only the direct route (as the crow flies) between Jisr ash Shughūr and Manbij has been calculated here.
Air line (approximately)
167 kilometers
90 nautical miles