How Combat Power (CP) Really Works in Pokémon GO

Combat Power (CP) is the number every new trainer fixates on, and the number every experienced trainer learns to distrust a little. It’s useful, but it’s also a compressed summary of four separate things happening under the hood: a Pokémon’s species, its level, and two of its three hidden Individual Values. Understanding the formula changes how you evaluate every Pokémon you catch.

The actual formula

Pokémon GO calculates CP like this:

CP = floor( (Attack × √Defense × √Stamina × CPM²) / 10 )

Where Attack, Defense and Stamina are each the species’ base stat plus its individual value (IV) for that stat (0–15), and CPM (Combat Power Multiplier) is a fixed number tied to the Pokémon’s level, running from roughly 0.094 at level 1 up to about 0.845 at level 51.

Why this formula matters more than it looks

Notice that Attack appears as a flat multiplier, while Defense and Stamina are both under square roots. That’s not a rounding quirk — it means Attack has a proportionally larger effect on CP than Defense or Stamina do. Two Pokémon with the same total IV sum (say, 45 out of a possible 45) can have meaningfully different CP depending on which stat that IV total is concentrated in, because a high Attack IV moves CP more than an equivalent Defense or Stamina IV would.

This is also why CP alone is a poor way to judge a Pokémon for PvP. A “high CP” Pokémon might have gotten there through inflated Attack at the cost of bulk — great for raids, potentially fragile in a Great League matchup where you want a specific, capped CP with balanced stats.

Level vs. CPM: why leveling up has diminishing returns

CPM doesn’t increase linearly with level — it flattens out considerably in the higher levels. The jump from level 1 to level 20 raises CPM more than six-fold, but the jump from level 40 to level 50 raises it by only a few percentage points. That’s why “fully powering up” a Pokémon from level 40 to 50 costs an enormous amount of Stardust and Candy for a comparatively small CP gain — the formula is intentionally designed to make early leveling cheap and late leveling expensive.

What this means for your Stardust

• For raiding, maximize a Pokémon’s CP with good Attack IVs first — raw damage matters more than bulk against a boss you’re not directly threatened by (unless you’re solo-raiding, in which case Defense and Stamina matter far more).
• For PvP leagues (Great League: 1500 CP cap, Ultra League: 2500 CP cap), you generally want high Defense and Stamina IVs and a lower Attack IV, because that combination lets a Pokémon reach a higher level (and therefore more overall bulk) before it hits the CP cap.
• Don’t fully power up a Pokémon before you know its role. Since late-level Stardust costs balloon while CP gains shrink, it’s more efficient to identify a Pokémon’s IV spread and intended use (raid attacker vs. PvP piece) before committing serious resources.

Check your own Pokémon

You don’t need to do this math by hand. Our CP Calculator projects CP at any level for a given IV spread, and our IV Calculator works backward from a Pokémon’s current CP and HP to tell you its likely IV range. Together, they turn “this number looks big” into an actual, informed decision about whether a Pokémon is worth your Stardust.

Why the same species can show wildly different CP

New players are often confused when they see two of the same Pokémon at the same level showing very different CP values in a friend’s collection or on a raid leaderboard. The answer is almost always IVs. Since Attack, Defense and Stamina IVs are assigned independently and randomly (0–15 each) at the moment of catching, the theoretical spread between the worst possible roll and the best possible roll of the same species and level is substantial — often several hundred CP at higher levels. This is also why “trap” evaluations based purely on a screenshot of someone else’s CP number, without knowing the level or IVs behind it, are unreliable.

A worked example

Take a Pokémon with base stats of Attack 200, Defense 180 and Stamina 190 (values in this range are typical for strong non-Legendary attackers). At level 20 (CPM ≈ 0.597) with perfect 15/15/15 IVs, that works out to CP 1,534. The same species at the same level with poor 4/4/4 IVs comes out to CP 1,375 — about 160 CP of difference from IVs alone, before you even factor in moveset. Multiply that gap across dozens of catches and it’s easy to see why serious raiders are selective about which individual Pokémon they invest Stardust into.

A quick myth to clear up

CP is not a direct measure of “how good” a Pokémon is in every context, and it’s not directly comparable between different species either — a level 20 Magikarp and a level 20 Dragonite can never reach the same CP no matter their IVs, because their base stats differ so dramatically. Use CP to compare individuals of the same species at the same level, and use dedicated PvP rankings or raid DPS (damage-per-second) charts to compare across different species for a specific purpose.