The calculated distance (air line) between Nice and Roquebrune-sur-Argens is approximately 36 miles respectively 58 kilometers.
By car or train, the actual journey to Roquebrune-sur-Argens is certainly longer, as only the direct route (as the crow flies) between Nice and Roquebrune-sur-Argens has been calculated here.
Air line (approximately)
58 kilometers
31 nautical miles