The calculated distance (air line) between Nyasvizh and Svyetlahorsk is approximately 134 miles respectively 215 kilometers.
By car or train, the actual journey to Svyetlahorsk is certainly longer, as only the direct route (as the crow flies) between Nyasvizh and Svyetlahorsk has been calculated here.
Air line (approximately)
215 kilometers
116 nautical miles