The calculated distance (air line) between Daugavgrīva and Aizkraukle is approximately 55 miles respectively 89 kilometers.
By car or train, the actual journey to Aizkraukle is certainly longer, as only the direct route (as the crow flies) between Daugavgrīva and Aizkraukle has been calculated here.
Air line (approximately)
89 kilometers
48 nautical miles