The calculated distance (air line) between Uusikaupunki and Seinäjoki is approximately 145 miles respectively 234 kilometers.
By car or train, the actual journey to Seinäjoki is certainly longer, as only the direct route (as the crow flies) between Uusikaupunki and Seinäjoki has been calculated here.
Air line (approximately)
234 kilometers
126 nautical miles