The calculated distance (air line) between Khān Shaykhūn and Dūmā is approximately 130 miles respectively 209 kilometers.
By car or train, the actual journey to Dūmā is certainly longer, as only the direct route (as the crow flies) between Khān Shaykhūn and Dūmā has been calculated here.
Air line (approximately)
209 kilometers
113 nautical miles