How many EV per level?
Each Pokemon can have a maximum of 510 EVs. One stat can have a maximum of 252 EVs (as of Generation 7) and 255 EVs prior to Generation 7.
What is the max EV for a Pokémon?
510 EVs
As of Sun and Moon, you can put a maximum of 252 EVs into a given stat, and a Pokémon can have a maximum of 510 EVs in total. Generally, in competitive play, trainers will put 252 EVs into two key stats, and the remaining handful into a third.
How do EV’s work Pokémon?

Effort Values, or EVs, are values for each stat (HP, attack, etc) that a Pokemon can gain through battling Pokemon or Super Training. Each Pokemon can earn up to 510 EV points before maxing out their EVs. These EV points influence your final stats and your scaling when you play Online Battles.
What’s EV in Pokémon?
EVs, or Effort Values, are bonus stats that your Pokémon will gain from defeating specific types of Pokémon. For example, beating a Gastly will give one special attack EV point and beating a Rookidee will give one speed EV point.
Can I EV train a LVL 100 Pokémon?
You need to have a total of 252 effort points in a particular stat to get the maximum possible effect of your EV training and the full 63-point boost once the Pokémon reaches Level 100.

Can I max EVs at level 1?
Nope. No matter what level you train them at, when they get to the same level, they will have the same stats.
Can you still EV train at level 100?
Do EXP candies make Pokémon weaker?
No. Rare Candies do absolutely nothing other than raise your level.
Does EV training matter?
Why Are EVs Important? EVs are important because they are another way of being able to improve your Pokemon besides just leveling them up. EV training allows players to target specific stats they want to increase on their Pokemon.
Are wild Pokémon weaker?
What are EVs? Ever wonder why NPCs in the Pokemon games always say that trained Pokemon are stronger than wild ones? The answer is actually quite simple: trained Pokemon have Effort Values, while wild Pokemon do not.