The calculated distance (air line) between Rebecq-Rognon and Sint-Niklaas is approximately 36 miles respectively 57 kilometers.
By car or train, the actual journey to Sint-Niklaas is certainly longer, as only the direct route (as the crow flies) between Rebecq-Rognon and Sint-Niklaas has been calculated here.
Air line (approximately)
57 kilometers
31 nautical miles