When to evolve it
Evolving early costs the base form's moves. Evolving late costs the evolved form's, and that is the half nobody writes down: the check the game runs the moment a Pokémon evolves is an exact-level match, never “at or below”. Level a Magikarp to 25 and the Gyarados will never learn Bite.
How this works
Level by level
Only the levels where the answer changes are listed. A green row costs nothing.