Rounds

Rounds  (also known as levels, waves, or stages) are the levels in the BTD series. Each round gets harder as the player progresses. The Red Bloon Equivalent (RBE), premiering in BTD4, shows how many pops to finish a round. In Bloons Tower Defense 4, the range of RBE is 92,881,116.

BTD5 overview
The max. for popping bloons is valid only if regrowth bloons that have multiple children do not regrow layers with multiple children (e. g. 1 Zebra --> 1 Black & 1 White --> 2 Zebra bloons).

Game video demonstrating the sequence of bloon generation

Trivia

 * In Bloons Tower Defense 4, round 1 has a higher RBE than the level in which the Camo Bloon debuts in level 24.
 * The final round in BTD4 (round 250) has an RBE of 2,881,116 or 999 BFBs.
 * Apopalypse Mode in Bloons Tower Defense 4 and Bloons Tower Defense 5 have rounds, but there are no pauses in-between each one.
 * The Red Bloon Equivalent is in the bank RBE.
 * There are more than 400 rounds on BTD5.
 * The highest round ever achieved in BTD5 was round 446 on Bloon-cricles in Hard mode.