Case 1
- Species catch rate
- 45
- Which ball?
- Poké Ball (×1)
- Status condition
- None (×1)
- Target's remaining HP
- 100%
0.0588
Open with these valuesPokémon Catch Rate Calculator
0.0588
Result: 0.0588Everything runs through one number, the modified catch rate X: lower the target's HP, put it to sleep, throw a better ball, and X climbs. The chance for a single throw is X divided by 255, and it is certain once X reaches 255. A catch rate of 45 at full health in a Poké Ball gives 0.0588 — about one throw in seventeen.
The numbers at a glance
Held fixed: Species catch rate 45, Which ball? Poké Ball (×1), Status condition None (×1).
| Target's remaining HP (%) | Result |
|---|---|
| 80 | 0.0824 |
| 85 | 0.0765 |
| 90 | 0.0706 |
| 95 | 0.0647 |
| 100Your value | 0.0588 |
Worked examples
Case 2
- Species catch rate
- 45
- Which ball?
- Ultra Ball (×2)
- Status condition
- Asleep or frozen (×2)
- Target's remaining HP
- 25%
0.5882
Open with these valuesCase 3
- Species catch rate
- 3
- Which ball?
- Ultra Ball (×2)
- Status condition
- Asleep or frozen (×2)
- Target's remaining HP
- 10%
0.0439
Open with these valuesHow it's calculated
X = (3 − 2 × HP share) ÷ 3 × rate × ball × status; chance = X ÷ 255
- StepLook up the species catch rate — 3 for most legendaries, 255 for early-route Pokémon.
- StepEnter the target's remaining HP as a percentage of its maximum.
- StepPick the ball and any status condition; both multiply the catch rate.
- ResultRead the chance for one throw — one divided by it is the average number of balls.
What this number means
Generation III and IV, reverse-engineered
The formula, the ball factors and the status factors come from a fan-run mechanics page checked on 25 August 2026, not from the publisher. They were read out of the games by the community, and later generations changed the constants.
X ÷ 255 is a design target, not a promise
The source itself only calls the chance roughly X/255, because the game rounds to whole numbers on the way there. Take the output as a solid estimate for one throw rather than a frame-perfect figure.
The Master Ball skips the formula
Picking it returns a chance of 1 whatever the catch rate, HP and status say. That mirrors the guaranteed catch; it is not a calculation.
HP is the lever that moves most
At full health the HP term sits at one third; near zero it climbs toward one and roughly triples X. A catch rate of 45 in a Poké Ball goes from 0.0588 to 0.1647 once the target is down to 10 %.
Commonly misread
A chance of 0.0588 means about six throws.
That is the chance per throw; one divided by it is about seventeen balls on average.
I play a recent game, so these numbers are exact for it.
This is the Generation III and IV formula. Later generations changed constants and added balls whose multipliers depend on the situation.
Poison keeps ticking, so it is the best status for catching.
Sleep and freeze give ×2 against ×1.5 for poison, and poison can knock the target out before you land the catch.
Better balls raise the chance without limit.
The chance stops at 1 once X reaches 255. A catch rate of 200 with an Ultra Ball, sleep and 20 % HP is already there.
Reference table
| Catch rate, ball, status, HP | Situation | Chance |
|---|---|---|
| 255, Poké Ball, none, 100 % | An early-route Pokémon, untouched | 0.3333 |
| 45, Poké Ball, none, 100 % | A typical wild Pokémon at full health | 0.0588 |
| 45, Poké Ball, none, 10 % | The same target worn down to a sliver | 0.1647 |
| 45, Poké Ball, asleep, 25 % | Low HP and sleep, cheapest ball | 0.2941 |
| 45, Ultra Ball, asleep, 25 % | All three levers pulled at once | 0.5882 |
| 3, Poké Ball, none, 100 % | A legendary with nothing prepared | 0.0039 |
| 3, Ultra Ball, asleep, 10 % | The same legendary, fully prepared | 0.0439 |
| 3, Master Ball, none, 100 % | The formula is skipped entirely | 1.0000 |
Questions
What does a Pokémon's catch rate mean?
The catch rate is a fixed number from 3 to 255 stored for each species, and higher means easier to catch. It is only the starting point: the game multiplies it by an HP factor, the ball and any status condition to get the modified rate X. A catch rate of 255 is nearly a free catch, while a 3 is brutally hard.
Why does lowering HP make a Pokémon easier to catch?
The formula contains the term (3 × HPmax − 2 × HPnow) ÷ (3 × HPmax). At full HP that equals one third, and as current HP approaches zero it climbs toward one, roughly tripling the modified catch rate. Weakening the target to a sliver of red HP is the single most reliable way to improve your odds.
How much does the ball matter?
A Poké Ball is ×1, a Great Ball ×1.5 and an Ultra Ball ×2, while a Master Ball skips the formula and always succeeds. The ball is a multiplier, so a better one helps but doubles at most. Against a low catch rate it can still leave you under 20 % per throw, which is why HP and status usually do more work.
Which status condition is best for catching?
Sleep and freeze give the largest bonus, ×2, and they also stop the target from attacking or fleeing. Paralysis, poison and burn give a smaller ×1.5. Sleep is usually preferred because poison and burn keep chipping away at HP and risk knocking the Pokémon out before you catch it.
How many balls will I need on average?
One divided by the per-throw chance: a chance of 0.05 means about 20 balls, a chance of 0.25 about four. Because every throw is independent this is a long-run average, and you might catch on the first ball or burn far more than the average on a bad run. Use it to decide whether to throw now or weaken the target further.
Will this match my exact game?
It uses the Generation III and IV formula, and the source calls the chance X ÷ 255 a design target that in-game integer rounding can shift by a little. Later generations changed constants and added situational balls such as Dusk, Net and Timer Balls whose multipliers depend on conditions. Treat the number as a solid estimate rather than a frame-perfect figure for one title.
Sources and last check
Information, not professional advice.