The calculated distance (air line) between Byalynichy and Navapolatsk is approximately 115 miles respectively 185 kilometers.
By car or train, the actual journey to Navapolatsk is certainly longer, as only the direct route (as the crow flies) between Byalynichy and Navapolatsk has been calculated here.
Air line (approximately)
185 kilometers
100 nautical miles