Translations:Effort values/3/en
From Pixelmon Wiki
The effects of EVs are applied immediately, and leveling up is not necessary to see their effects. At lower levels, it will take more EVs to equal 1 stat point (e.g. 8 EVs per stat point at level 50), but as levels are gained, the contribution of the existing EVs to stats will eventually reach the 4:1 ratio at level 100.