The calculated distance (air line) between Ratnapura and Dehiwala-Mount Lavinia is approximately 38 miles respectively 61 kilometers.
By car or train, the actual journey to Dehiwala-Mount Lavinia is certainly longer, as only the direct route (as the crow flies) between Ratnapura and Dehiwala-Mount Lavinia has been calculated here.
Air line (approximately)
61 kilometers
33 nautical miles