Complex sentence: The size of the "Kirov" class, at approximately 28,000 tons full load, around the same size as a First World War battleship, and significantly bigger than any contemporary cruiser design, led to commentators in the west describing them as "battlecruisers".
Split into simpler sentences: The size of the "Kirov" class was approximately 28,000 tons full load. This was around the same size as a First World War battleship, and significantly bigger than any contemporary cruiser design, leading to commentators in the west describing them as "battlecruisers".