The calculated distance (air line) between Heist-op-den-Berg and La Louvière is approximately 47 miles respectively 76 kilometers.
By car or train, the actual journey to La Louvière is certainly longer, as only the direct route (as the crow flies) between Heist-op-den-Berg and La Louvière has been calculated here.
Air line (approximately)
76 kilometers
41 nautical miles