Catch Rate Calculator — Calculate Your Capture Probability & Success Rate

Optimize every capture attempt with the most accurate catch rate calculator. Compute capture probability using ball type, HP, status effects, and species catch modifiers for any creature.

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Catch Rate Calculator

Enter the target creature's stats, select your ball type and any status effect to compute your exact capture probability and expected shake checks.

Fill in the creature's stats, choose your ball and status, then click Calculate Catch Rate to see your capture probability.

Catch Rate Formula Explained

The catch rate formula determines your probability of successfully capturing a creature. It combines HP factor, species catch rate, ball modifier, and status effect multiplier to compute the final capture chance.

Modified Catch Rate (a) = ((3 × MaxHP − 2 × CurrentHP) × CatchRate × BallMod) / (3 × MaxHP) × StatusMod
Capture Probability = (b / 255)4 × 100%   where b = min(255, round(a))

Ball Type Multiplier Reference

Ball TypeMultiplierBest Use Case
Poke Ball1×Common creatures, early game
Great Ball1.5×Mid-tier creatures
Ultra Ball2×High-level creatures
Master Ball255×Guaranteed capture
Dusk Ball3.5×Caves or nighttime
Net Ball3×Water or Bug types

The species catch rate ranges from 3 (hardest to catch) to 255 (easiest). Lowering HP and applying status effects are the most reliable ways to improve your odds without using rarer balls.

How Catch Rate Calculation Works

Understanding the catch rate formula gives you the edge in every capture encounter. Follow these steps to maximize your success rate:

  1. Weaken the target — Reduce the creature's HP as low as possible. At 1 HP, the HP factor approaches its maximum of nearly 3×, dramatically boosting your modified catch rate.
  2. Apply a status effect — Sleep and Freeze provide a 2× multiplier. Paralysis, Poison, and Burn provide 1.5×. These do not stack, so apply the strongest available status.
  3. Select the best ball — Match the ball to the situation. Ultra Balls provide a reliable 2×, while specialized balls like Dusk Balls (3.5× in caves) can outperform in specific conditions.
  4. Know the species catch rate — Each creature species has a base catch rate from 3 to 255. Lower values mean naturally harder captures requiring more preparation.
  5. Compute modified catch rate — The formula combines all factors: a = ((3 × MaxHP − 2 × CurrentHP) × CatchRate × BallMod) / (3 × MaxHP) × StatusMod
  6. Calculate capture probability — Cap the result at 255, then raise (b/255) to the 4th power for the final probability. Four shake checks must all pass for a successful capture.

Catch Rate Calculation Examples

Example 1: Common Creature with Ultra Ball at Half HP

Max HP: 100 | Current HP: 50 | Catch Rate: 120 | Ball: Ultra Ball (2×) | Status: None

a = ((300 − 100) × 120 × 2) / 300 × 1 = 160
b = min(255, 160) = 160
Capture Probability = (160/255)4 = 15.5%

Example 2: Rare Creature at Low HP with Sleep

Max HP: 200 | Current HP: 10 | Catch Rate: 45 | Ball: Great Ball (1.5×) | Status: Sleep (2×)

a = ((600 − 20) × 45 × 1.5) / 600 × 2 = 130.5 → b = 130
Capture Probability = (130/255)4 = 6.8%

Example 3: Legendary Creature with Dusk Ball at Night

Max HP: 250 | Current HP: 1 | Catch Rate: 3 | Ball: Dusk Ball (3.5×) | Status: Sleep (2×)

a = ((750 − 2) × 3 × 3.5) / 750 × 2 = 20.9 → b = 20
Capture Probability = (20/255)4 = 0.038% per attempt

Even with optimal conditions, creatures with very low catch rates require patience and multiple attempts. Stock up on the best balls available.

Capture Probability Mechanics & Shake Checks

When you throw a ball, the game performs up to four shake checks. The ball shakes after each successful check. If all four checks pass, the capture succeeds. If any check fails, the ball breaks open.

Shake Check Probability

Each individual shake check has a probability of (b/255) of passing, where b is the capped modified catch rate. The overall capture probability is the product of all four independent checks:

Overall Capture % = (b/255) × (b/255) × (b/255) × (b/255) × 100

Shake Check Outcomes by Modified Catch Rate

Modified Catch Rate (b)Per-Shake ChanceOverall Capture %Expected Outcome
255100%100%Guaranteed capture
20078.4%37.8%~1 in 3 attempts
15058.8%11.9%~1 in 8 attempts
10039.2%2.4%~1 in 42 attempts
5019.6%0.15%~1 in 667 attempts
207.8%0.004%~1 in 26,000 attempts

A modified catch rate above 200 gives a solid capture chance. Values below 100 make capture extremely unlikely without repeated attempts and optimal conditions.

People Also Ask About Catch Rate Calculations

Catch rate is calculated using the modified catch rate formula: a = ((3 × MaxHP - 2 × CurrentHP) × CatchRate × BallModifier) / (3 × MaxHP) × StatusModifier. The result is capped at 255. The capture probability is approximately (a/255)^4, meaning four shake checks must all succeed for a successful capture. Lower HP, stronger balls, and status effects all improve your odds.
A Master Ball guarantees capture with a 255× multiplier, making it impossible to fail. For standard balls, the Ultra Ball provides a 2× multiplier, while specialized balls like the Dusk Ball (3.5× in dark conditions) and Net Ball (3× for water/bug types) can outperform Ultra Balls in specific situations. Quick Balls offer 2.5× on the first turn of combat.
Status effects apply a multiplier to the modified catch rate. Sleep and Freeze provide the highest bonus at 2×, effectively doubling your capture probability. Paralysis, Poison, and Burn provide a 1.5× multiplier. Status effects do not stack; only the highest applicable multiplier is used. Applying Sleep or Freeze is the most effective strategy for difficult captures.
Yes, lowering the target's HP is one of the most effective ways to increase catch rate. When HP drops to 1, the HP factor approaches its maximum value of nearly 3, almost tripling the modified catch rate compared to full HP. Reducing HP to the red zone (below 20%) combined with a status effect and the best available ball gives the highest capture probability.
Species catch rates range from 3 (hardest) to 255 (easiest). Values above 200 are very easy to catch even at full HP with a basic ball. Values between 90-150 represent average difficulty. Catch rates below 45 are considered very difficult and require careful HP reduction, status effects, and the best available balls. Legendary creatures typically have catch rates between 3 and 45.

Frequently Asked Catch Rate Calculator Questions

This calculator uses the widely adopted catch rate formula found in many creature collection games. While the core mechanics are consistent across many titles, individual games may have slight variations in ball multipliers, status effects, or additional modifiers. Always verify against your specific game's mechanics if precise values differ.
The species catch rate is a base value assigned to each creature type, typically ranging from 3 to 255. A higher number means the creature is easier to catch. This value directly multiplies into the modified catch rate formula. Common early-game creatures often have catch rates above 200, while rare and legendary creatures have values as low as 3.
No. The Master Ball uses a 255× multiplier, which effectively bypasses the entire catch rate formula. When the modified catch rate reaches 255, the shake check probability becomes 100%, and the overall capture probability is guaranteed at 100%. A Master Ball will never fail regardless of the target's HP, status, or species catch rate.
The calculator implements the standard catch rate formula with precise rounding at each step, matching the mechanics used in most creature collection games. Results are accurate to within 0.1% for the modified catch rate calculation. Note that in-game RNG (random number generation) introduces natural variance; a calculated 50% capture chance means approximately half of your attempts should succeed over a large sample size.
The lowest possible HP (1 HP) gives the maximum HP factor. At 1 HP, the formula term (3×MaxHP - 2×CurrentHP) approaches 3×MaxHP, maximizing the numerator. Always aim to reduce the target to 1 HP for the best odds. Using False Swipe or similar moves that leave at least 1 HP is the safest strategy to avoid accidentally defeating the target.
No, status effects do not stack for catch rate purposes. Only the single highest applicable status multiplier is used in the formula. If a target is both Paralyzed and Poisoned, only one 1.5× multiplier applies. Since Sleep and Freeze provide the highest multiplier at 2×, they are the preferred status conditions for maximizing capture probability.

Catch Rate Calculator Glossary

Species Catch Rate

The base catch difficulty value assigned to each creature species, ranging from 3 (hardest) to 255 (easiest). Higher values mean easier captures.

Ball Modifier

A multiplier applied by the type of ball used. Standard balls range from 1× to 2×, while specialized balls can reach 3.5× under specific conditions.

Status Effect Multiplier

The catch rate bonus from status conditions. Sleep and Freeze provide 2×, while Paralysis, Poison, and Burn provide 1.5×. Only the highest multiplier applies.

Modified Catch Rate (a)

The intermediate value calculated by combining HP factor, species catch rate, ball modifier, and status multiplier. Capped at 255 for the shake check calculation.

Shake Check

One of four independent probability checks performed after throwing a ball. Each check passes with probability (b/255). All four must pass for capture to succeed.

HP Factor

The ratio (3×MaxHP - 2×CurrentHP) / (3×MaxHP) that rewards weakening the target. Approaches 3× at 1 HP and 1× at full HP.

Critical Capture

A rare event where only one shake check is performed instead of four, dramatically increasing capture probability. Chance increases with Pokedex completion.

Guaranteed Capture

When the modified catch rate reaches 255, all four shake checks pass with 100% probability, ensuring capture. Master Balls always achieve this state.

Editorial Review & Methodology

This catch rate calculator was built and reviewed by the NumbrWiz Editorial Team. The catch rate formula and ball modifiers are based on comprehensive analysis of creature collection game mechanics, community-verified data, and cross-referencing with official game documentation where available.

  • Formula verification: Cross-checked against established catch rate formulas from major creature collection game series, community wikis, and decompiled game code analyses.
  • Edge case testing: Tested with minimum and maximum HP values, all ball types, all status effects, and species catch rates across the full 3-255 range.
  • UX review: Designed for intuitive input with clear validation messages, step-by-step formula breakdown, and accessible result presentation.

Transparency note: All calculations run client-side in your browser. No data is ever collected, stored, or transmitted. This is an unofficial fan utility tool. Results are for planning and educational purposes; actual in-game values may vary with updates or between different game titles. Verify critical calculations independently.

Page last reviewed: May 2026 · NumbrWiz Editorial Team