What does 'IV' mean in Pokémon GO?

IV stands for “Individual Value”

In Pokémon Go, IV’s are different for every Pokémon. Your Pikachu will have different IV’s than your friend’s Pikachu, and it’ll also be different from a Weedle you caught.

There are three IV’s that are added onto a Pokémon's base stats. Each Pokémon species has a set base stat of Attack, Defense, and Stamina.

You can find them here: Pokemon GO Tools, References, and Stats

IV ranges from 0–15, and they are added to a Pokémon's base stat.

The higher the better, so a Pikachu with IV’s of

15 Atk

14 Def

15 Stamina

would be more competitively viable than a Pikachu with IV’s of

10 Atk

2 Def

4 Stamina

The above Pikachu has a total of 44/45, which makes it 97% perfect, while

the below Pikachu has a total of 16/45 which makes it 35% perfect.

A Pokémon should be above 75% perfect to be used competitively.

To find the IV’s of your Pokemon, visit my answer: How does the new appraisal system work in Pokémon GO?