The calculated distance (air line) between Rio de Janeiro and Duque de Caxias is approximately 12 miles respectively 19 kilometers.
By car or train, the actual journey to Duque de Caxias is certainly longer, as only the direct route (as the crow flies) between Rio de Janeiro and Duque de Caxias has been calculated here.
Air line (approximately)
19 kilometers
10 nautical miles