How does the Pokémon catch rate formula work?

The core formula calculates a modified catch rate based on the Pokémon's remaining HP (lower HP = higher catch rate), its base catch rate (species difficulty), the Poké Ball bonus multiplier, and status condition bonus. Four independent 'shake' checks occur — all four must pass for capture. Ultra Ball + Sleep + low HP dramatically improves odds.

What is the best ball for catching legendaries?

For cave or nighttime encounters: Dusk Ball (3.5×) is often the best readily available option. Timer Ball (4× after 10 turns) is excellent if you have infinite turns. Quick Ball (5×) on the very first turn has high immediate value. For water legendaries: Net Ball if they're Water-type. Master Ball guarantees capture, best saved for roaming legendaries or Poké Ball-only encounters.

Does sleeping a Pokémon really help catch it?

Yes significantly — Sleep and Freeze apply a 2.5× multiplier to the catch rate. Paralysis/Burn/Poison give 1.5×. For legendary Pokémon with base catch rate 3, the difference between no status (catch rate 3) and Sleep (catch rate 7.5) is substantial — roughly tripling your probability per ball. Always use a sleep-inducing move before throwing balls at legendaries.

What does base catch rate mean in Pokémon?

Base catch rate is a species-specific value from 3 (hardest: legendaries and rare mythicals) to 255 (easiest: common route Pokémon that are always catchable). This value is modified by HP, ball type, and status to calculate actual capture probability. A Pokémon with base catch rate 255 is essentially guaranteed in any Poké Ball; base rate 3 requires perfect conditions and multiple attempts.

How Pokémon Catch Rate Is Calculated: Formulas, Balls, and Probability

Understand the Pokémon catch rate formula — how HP, status conditions, ball type, and base catch rate combine to calculate the probability of catching any Pokémon.

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The Pokémon Catch Rate Formula (Gen III+)

The modern Pokémon capture calculation (Gen III through current) uses a multi-step formula:

Step 1: Calculate modified catch rate a = ((3 × Max HP − 2 × Current HP) / (3 × Max HP)) × Base Catch Rate × Ball Bonus × Status Bonus

Step 2: Shake probability per shake p = 65,536 / (255/a)^0.1875

Step 3: Four shakes needed P(capture) = (p/65,536)^4

Base Catch Rate by Pokémon Category

Category	Base Catch Rate	Example
Common wild Pokémon	255 (100%)	Pidgey, Rattata
Standard wild	127–200	Eevee (45), Gastly (190)
Rare Pokémon	25–75	Dratini (45), Snorlax (25)
Pseudo-legendaries	3–45	Dragonite (45), Garchomp (45)
Legendary birds	3–5	Articuno/Zapdos/Moltres (3)
Mythical	3–45	Celebi (45), Darkrai (3)
Ultra Beasts	255 (special calc)	Nihilego, Buzzwole

Mew, Arceus, many legendaries: Base catch rate = 3 (very hard)

Poké Ball Bonus Multipliers

Ball	Bonus Multiplier	Condition
Poké Ball	1×	Standard
Great Ball	1.5×	Standard
Ultra Ball	2×	Standard
Master Ball	Guaranteed	Always
Dusk Ball	3.5×	Night or cave
Net Ball	3.5×	Water/Bug types
Timer Ball	4× (max, 10+ turns)	After 10 turns
Quick Ball	5×	On first turn only
Repeat Ball	3.5×	Previously caught species
Heavy Ball	−20 to +30 bonus to base rate	Based on Pokémon weight

Status Condition Bonuses

Status	Modifier
None	1×
Paralysis	1.5×
Poison	1.5×
Burn	1.5×
Asleep	2.5×
Frozen	2.5×

Practical effect: Sleep or freeze doubles catch rate. For legendaries with catch rate 3, use Sleep + Dusk Ball at night + low HP to maximize odds.

Worked Example: Catching Articuno

Articuno: Max HP ≈ 195 (Level 50), Base catch rate = 3

Optimal setup: Articuno at 1 HP (frozen), Dusk Ball at night (3.5× bonus)

a = ((3×195 − 2×1) / (3×195)) × 3 × 3.5 × 2.5 = (583/585) × 3 × 3.5 × 2.5 = 0.9966 × 26.25 = 26.2

p = 65,536 / (255/26.2)^0.1875 = 65,536 / 9.74^0.1875 ≈ 65,536 / 1.477 ≈ 44,368

P(one ball catches) = (44,368/65,536)^4 ≈ (0.677)^4 ≈ 21.0% per ball

Expected balls to catch: 1/0.210 ≈ 4–5 Dusk Balls on average

Maximizing Catch Rate: Prioritization

Reduce HP to 1–2 (as close to 0 as possible)
Apply Sleep or Freeze (2.5× bonus)
Choose the best situational ball (Dusk, Timer, Net, Quick)
Use False Swipe to safely reach exactly 1 HP without KO

Related Guides

Frequently Asked Questions

How does the Pokémon catch rate formula work?: The core formula calculates a modified catch rate based on the Pokémon's remaining HP (lower HP = higher catch rate), its base catch rate (species difficulty), the Poké Ball bonus multiplier, and status condition bonus. Four independent 'shake' checks occur — all four must pass for capture. Ultra Ball + Sleep + low HP dramatically improves odds.
What is the best ball for catching legendaries?: For cave or nighttime encounters: Dusk Ball (3.5×) is often the best readily available option. Timer Ball (4× after 10 turns) is excellent if you have infinite turns. Quick Ball (5×) on the very first turn has high immediate value. For water legendaries: Net Ball if they're Water-type. Master Ball guarantees capture, best saved for roaming legendaries or Poké Ball-only encounters.
Does sleeping a Pokémon really help catch it?: Yes significantly — Sleep and Freeze apply a 2.5× multiplier to the catch rate. Paralysis/Burn/Poison give 1.5×. For legendary Pokémon with base catch rate 3, the difference between no status (catch rate 3) and Sleep (catch rate 7.5) is substantial — roughly tripling your probability per ball. Always use a sleep-inducing move before throwing balls at legendaries.
What does base catch rate mean in Pokémon?: Base catch rate is a species-specific value from 3 (hardest: legendaries and rare mythicals) to 255 (easiest: common route Pokémon that are always catchable). This value is modified by HP, ball type, and status to calculate actual capture probability. A Pokémon with base catch rate 255 is essentially guaranteed in any Poké Ball; base rate 3 requires perfect conditions and multiple attempts.

Last updated 7/28/2026