Stat (GO)
These are the stats in Pokémon GO.
Pokémon have HP, Attack, and Defense stats, as well as CP to summarize former three. Unlike the core games, Pokémon GO makes no distinction between physical or special damage; instead, all attacks simply use Attack and Defense to calculate damage. Of these four values in Pokémon GO, only HP and CP are directly visible. Since version 0.149.0, players can also directly see a Pokémon's IVs using the Appraise feature.
 For more information on how damage is calculated in GO, see Damage → Pokémon GO.
Determination of stats
Calculating a Pokémon's stats in Pokémon GO depends on its species' base stats, its IVs, and Power Up level. Whereas the core games have many variables in which one Pokémon's stats can become different from another's, in Pokémon GO, ultimately only a Pokémon's IVs will distinguish its stats from another of the same species and form.
The formula for all three basic stats are
where
base
refers to the relevant base statIV
refers to the IV for the stat in questionCPM
is the CP multiplier, which is determined by the Pokémon's current Power Up level. For HP, the final result is rounded down to the nearest integer, with a minimum value of 10.
Pokémon defending a Gym also have twice their regular HP during Gym battles.
CP
Combat Power (Japanese: 総合的な強さ Total Power), abbreviated as CP (Japanese: CP), is a value derived from all three base stats to roughly indicate a Pokémon's capability in battle. This means that two Pokémon of the same species with the same CP may still have different underlying stats.
The formula for CP uses the values of the stats resulting from the formula above:
Like with HP, the value for CP is floored at 10, regardless of the Pokémon's actual stats. The calculation also does not round off stat values, and it uses the HP value before it is floored at 10.
Since Attack is factored directly into the formula for CP while HP and Defense are only factored in after taking their square root, this gives Attack a greater influence on the final value of CP than the other two stats.
Inbattle modification
Since February 15, 2019, in Trainer Battles, some Charged Attacks have a chance of modifying either the user's or target's Attack and/or Defense stats after it is cast, regardless if the target uses a Protect Shield. These stats are undone if the Pokémon is switched out.
 For a full list of these moves and their effects, see List of Charged Attacks
Stage  4  3  2  1  0  +1  +2  +3  +4 

Multiplier  ^{4}/_{8}  ^{4}/_{7}  ^{4}/_{6}  ^{4}/_{5}  ^{4}/_{4}  ^{5}/_{4}  ^{6}/_{4}  ^{7}/_{4}  ^{8}/_{4} 
Base stat conversion from the core series
Each Pokémon's base stats are based off its stats from the core series. Base stats for Pokémon and forms introduced in Generations I and II are calculated using the base stats from the Generation VI core series. Base stats for Pokémon and forms introduced Generation III and onward are based off their Generations VII and VIII base stats.
Aside from a few outliers, such as Shedinja's HP, base stats in GO can be derived by the following formulas: ^{[1]}
where
HP
is the HP stat from the core seriesAttack
is the Attack stat from the core seriesDefense
is the Defense and stat from the core seriesSpAtk
is the Sp. Attack stat from the core seriesSpDef
and Sp. Defense stat from the core seriesSpeed
is the Speed stat from the core series
After these calculations, if a Pokémon has a maximum CP of over 4,000, then for balancing purposes, all its base stats will be multiplied by 0.91. This reduction is not applied for Mega Evolutions.
Trivia
 Qwilfish and its Hisuian variant have different base stats in Pokémon GO, despite having identical stats in the core games. This is because Qwilfish had already existed in Pokémon GO before its stats were buffed in Generation VII.
In other languages
Stat

Combat Power
 
Hit Points

Attack

Defense

References
This article is part of Project Sidegames, a Bulbapedia project that aims to write comprehensive articles on the Pokémon Sidegames. 