The calculated distance (air line) between Jēkabpils and Aizkraukle is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to Aizkraukle is certainly longer, as only the direct route (as the crow flies) between Jēkabpils and Aizkraukle has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles