Pokemon Catch Rate Calculator
Estimate your odds of catching any Pokemon. Enter the species catch rate, HP remaining, ball type and status to get the capture chance per throw, with the formula.
Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser
Estimates capture chance per throw using the standard Generation III–VIII catch formula.
Show the formula & steps
How the Pokemon Catch Rate Calculator Works
Wondering whether that Ultra Ball will actually stick? This calculator estimates your capture chance per throw for any wild Pokemon in the main-series games. Enter the species catch rate, the percentage of HP remaining, the Poke Ball you are using and any status condition, and it returns the modified catch value, the per-throw probability, and roughly how many throws you need for a 95% chance of success.
The Formula
The games use a two-stage system. First a modified catch value a is calculated:
a = ((3 × HPmax − 2 × HPcurrent) × catchRate × ballBonus × statusBonus) ÷ (3 × HPmax)
If a is 255 or greater, the Pokemon is caught automatically. Otherwise the game derives a shake value b:
b = 1,048,560 ÷ √√(16,711,680 ÷ a)
A ball performs four shake checks, each succeeding with probability b ÷ 65536. The Pokemon is caught only if all four pass, so:
Catch chance = (b ÷ 65536)⁴
Worked Example
Suppose you face a wild Pokemon with a catch rate of 45, knocked down to 30% HP, asleep (×2.5), and you throw an Ultra Ball (×2):
- HP factor = (3 − 2 × 0.30) ÷ 3 = 0.80
- a = 0.80 × 45 × 2 × 2.5 = 180
- Because a is below 255, b = 1,048,560 ÷ √√(16,711,680 ÷ 180) ≈ 60,070
- Catch chance = (60,070 ÷ 65,536)⁴ ≈ 70.6% per throw
At roughly 71% per throw, you would need only about 3 throws for a 95% cumulative chance of capturing it.
Tips to Maximise Your Odds
| Action | Effect on catch value |
|---|---|
| Reduce HP to red zone | HP factor up to ~×1 (vs ~×0.33 at full) |
| Inflict Sleep or Freeze | ×2.5 status bonus |
| Inflict Paralysis/Burn/Poison | ×1.5 status bonus |
| Switch from Poke Ball to Ultra Ball | ×2 ball bonus |
| Use a Master Ball | Guaranteed capture |
Combining a low-HP, status-afflicted target with a strong ball stacks every multiplier in the formula, which is why a Master Ball — the only ball that ignores the math entirely — is reserved for the hardest legendaries. This calculator runs entirely in your browser and is part of our gaming calculators collection.
Frequently asked questions
How is a Pokemon's catch rate calculated?+
The game first computes a modified catch value a = ((3 × max HP − 2 × current HP) × species catch rate × ball bonus × status bonus) ÷ (3 × max HP). If a is 255 or more the catch is guaranteed. Otherwise a shake value b is derived and the per-throw chance equals (b ÷ 65536) to the fourth power.
What is the species catch rate?+
Every Pokemon species has a fixed catch rate from 0 to 255 that you can look up on resources like Bulbapedia. Higher numbers are easier to catch — Caterpie is 255 while legendaries such as Mewtwo are only 3. Enter that number in the calculator.
Why does lowering HP improve my catch chance?+
The formula multiplies by (3 × max HP − 2 × current HP), so the lower the target's current HP, the larger that term becomes. Bringing a Pokemon into the red roughly triples the HP factor compared with full health, which is why trainers weaken Pokemon before throwing a ball.
How much do status conditions help?+
Sleep and Freeze apply the strongest multiplier (×2.5 in modern games), while Paralysis, Burn and Poison apply ×1.5. Because the bonus multiplies the whole catch value, putting a target to sleep can more than double your odds on top of the HP and ball bonuses.
Does this calculator work for every Pokemon game?+
It uses the core Generation III through VIII capture mechanics, which apply to the main-series games on Game Boy Advance, DS, 3DS and Switch. Pokemon GO and the Let's Go titles use different systems, so the percentages here are for the traditional turn-based games.