Originally Posted by Darkprince410

Fold itself simply denotes multiplication, not a specific number to work with. As such, Kaiou-sama's comment about Gokuu not using beyond the two-fold simply refers to not multiplying his battle power beyond a factor of two. The Kaiou-ken and the Kaiou-ken 2x are alternate names of the same technique, as this fact is confirmed by the Daizenshuu due to the battle powers they list. As such, ignore that they have two separate names, as that's the only thing that distingushes the two.

As srp76 mentioned, the base number used for Kaiou-ken is Gokuu's battle power, so Kaiou-ken/Kaiou-ken 2x simply doubles the base number, and as a result, Kaiou-ken 3x would triple the base number.