What level does Ivysaur evolve into Venusaur?

Ivysaur evolves through leveling up. Beginning at level 32, it evolves into Venusaur. Venusaur is the final evolution of the line beginning with Bulbasaur.
If an evolution is delayed (because the wild Pokemon chose not to evolve, or the trainer cancels the evolution), the Pokemon will continue trying to evolve each time it levels up after the level listed. Holding an Everstone will prevent Pokemon from evolving through leveling up.