The calculated distance (air line) between Porto Alegre and Arroio dos Ratos is approximately 30 miles respectively 48 kilometers.
By car or train, the actual journey to Arroio dos Ratos is certainly longer, as only the direct route (as the crow flies) between Porto Alegre and Arroio dos Ratos has been calculated here.
Air line (approximately)
48 kilometers
26 nautical miles