Ultra Sun Catch Rate Calculator
Calculate the exact probability of catching any Pokémon in Pokémon Ultra Sun with advanced modifiers
Ultimate Guide to Pokémon Ultra Sun Catch Rate Calculator
The catch rate mechanic in Pokémon Ultra Sun represents one of the most complex and rewarding systems in the entire franchise. Unlike earlier generations where catch rates followed simpler formulas, Generation 7 introduced multiple layers of modifiers that can dramatically alter your success rate. This comprehensive guide will explore every aspect of the catch rate calculation system, from base mechanics to advanced strategies for capturing even the rarest legendary Pokémon.
Understanding Base Catch Rates
Every Pokémon species in Ultra Sun has an intrinsic base catch rate value that serves as the foundation for all calculations. These values range from 3 (extremely difficult to catch) to 255 (guaranteed catch with any ball). Here’s a breakdown of common catch rate tiers:
- 255: Common Pokémon (e.g., Pikachu, Eevee, most early-game Pokémon)
- 120-200: Mid-tier Pokémon (e.g., many evolved forms, some rare spawns)
- 45-90: Rare Pokémon (e.g., starters in the wild, pseudo-legendaries)
- 3-45: Legendary and Mythical Pokémon (e.g., Mewtwo, Lugia, Ultra Beasts)
| Pokémon | Base Catch Rate | Category |
|---|---|---|
| Pikachu | 190 | Common |
| Charizard | 45 | Rare |
| Snorlax | 25 | Very Rare |
| Mewtwo | 3 | Legendary |
| Necrozma | 3 | Legendary |
| Tapu Koko | 3 | Guardian Deity |
| Ultra Beast (e.g., Buzzwole) | 10-30 | Ultra Beast |
The Catch Rate Formula in Generation 7
The core catch rate calculation in Ultra Sun follows this modified formula from previous generations:
Modified Catch Rate = (3 × HP_max × catch_rate × ball_bonus × status_bonus) / (3 × HP_current)
Where:
- HP_max: Pokémon’s maximum HP
- catch_rate: Pokémon’s base catch rate
- ball_bonus: Multiplier based on Poké Ball type
- status_bonus: Multiplier based on status condition (1× for none, 1.5× for sleep/freeze, 2× for others)
- HP_current: Pokémon’s current HP
After calculating the modified catch rate, the game performs up to 4 “shake checks” to determine if the catch succeeds. Each shake has a probability of success based on the modified catch rate:
| Shake Number | Probability Formula | Approx. Chance at Rate=50 |
|---|---|---|
| 1st Shake | a = floor((3 × HP_max × catch_rate × ball_bonus × status_bonus) / (3 × HP_current)) | ~68% |
| 2nd Shake | b = floor((a × 1048560) / 65536) / 255 | ~41% |
| 3rd Shake | c = floor((b × 1048560) / 65536) / 255 | ~25% |
| 4th Shake (Capture) | d = floor((c × 1048560) / 65536) / 255 | ~15% |
Poké Ball Multipliers in Ultra Sun
The choice of Poké Ball has a massive impact on catch rates. Ultra Sun introduced several new ball types and modified existing multipliers:
- Master Ball: 255× (100% catch rate, ignores all other factors)
- Ultra Ball: 2×
- Great Ball: 1.5×
- Poké Ball: 1× (base multiplier)
- Safari Ball: 1.5× (Wormhole encounters only)
- Net Ball: 3.5× vs Water/Bug types, 1× otherwise
- Dive Ball: 3.5× if fishing/underwater, 1× otherwise
- Nest Ball: (40 – level)/10 × (min 1, max 4)
- Repeat Ball: 3× if already caught, 1× otherwise
- Timer Ball: (turns + 10)/10 × (min 1, max 4)
- Dusk Ball: 3× at night/in caves, 1× otherwise
- Quick Ball: 5× on first turn, 1× otherwise
- Beast Ball: 0.1× vs non-Ultra Beasts, 5× vs Ultra Beasts
Advanced Catch Rate Modifiers
Ultra Sun introduced several new mechanics that can significantly boost catch rates:
- Catch Power: Activated through Festival Plaza, provides +1 to +3 levels of catch rate bonus (1.2× to 2× multiplier)
- Critical Catch: When HP is ≤ 1/3 of max, the catch rate is effectively doubled for the first shake check
- Shiny Bonus: Shiny Pokémon receive a hidden 1.5× catch rate multiplier
- Fishing/Cave Bonuses: Certain balls (Dusk Ball, Dive Ball) get enhanced multipliers in specific environments
- Ultra Wormhole Encounters: Pokémon caught in wormholes have modified catch rates and often require specific ball types
Optimal Strategies for Legendary Pokémon
Capturing legendary Pokémon in Ultra Sun requires careful preparation. Here’s a step-by-step optimal strategy:
- Reduce HP to 1: Use False Swipe (never brings HP to 0) or hold a Focus Sash
- Inflict Status: Sleep or Freeze provide the best bonuses (1.5×)
- Choose the Right Ball:
- Ultra Beasts: Beast Ball (5× multiplier)
- Regular Legendaries: Timer Ball (after 10+ turns) or Dusk Ball (if in cave/at night)
- Water Legendaries: Net Ball or Dive Ball
- Activate Catch Power: Level 3 provides a 2× multiplier
- Use Adrenaline Orb: Guarantees critical hit (useful with False Swipe)
- Save Before Attempting: Legendaries have ~1-5% catch rates even with optimal setup
Mathematical Breakdown of a Sample Capture
Let’s examine the catch rate calculation for a Level 60 Giratina (catch rate = 3) with these conditions:
- HP: 1/200 (red zone)
- Status: Sleep (1.5×)
- Ball: Dusk Ball in cave (3×)
- Catch Power: Level 3 (2×)
- Turns: 15 (Timer Ball would be 2.5×, but we’re using Dusk Ball)
- Critical Catch: Yes (HP ≤ 1/3, so first shake check is effectively doubled)
Calculation:
Modified Rate = (3 × 200 × 3 × 3 × 1.5 × 2) / (3 × 1) = 5400
First shake probability: min(255, floor(5400 × 2)) / 255 ≈ 100% (due to critical catch doubling)
Second shake: floor(5400 × 1048560 / 65536) / 255 ≈ 255 → 100%
Third shake: same calculation → 100%
Result: Guaranteed capture on first attempt with these conditions
Common Mistakes to Avoid
Even experienced players make these catch rate errors:
- Using the wrong ball type: Beast Ball is terrible against non-Ultra Beasts (0.1× multiplier)
- Ignoring status conditions: Burn/Poison (2×) is better than Sleep/Freeze (1.5×) despite common belief
- Forgetting Catch Power: The 2× multiplier from Level 3 is equivalent to using a Master Ball in some cases
- Not accounting for HP zones: The difference between yellow (1-29%) and red (1-9%) HP is significant
- Overlooking environment: Dusk Ball in caves vs. Timer Ball after 30 turns can be a 3× vs. 4× difference
Data-Driven Catch Rate Optimization
Based on extensive testing by the Pokémon research community (notably from Smogon and Bulbapedia), here are the empirically best setups for different scenarios:
| Scenario | Optimal Ball | Best Status | Estimated Rate | Shakes to Expect |
|---|---|---|---|---|
| Ultra Beast (e.g., Buzzwole) | Beast Ball | Sleep | ~12% | 1-2 |
| Legendary (e.g., Lugia) | Timer Ball (turn 30+) | Burn | ~8% | 1 |
| Common Pokémon (e.g., Pikachu) | Quick Ball (turn 1) | None | ~95% | 3-4 |
| Water Pokémon (e.g., Lapras) | Dive Ball | Paralysis | ~35% | 2-3 |
| Cave Pokémon (e.g., Zubat) | Dusk Ball | Freeze | ~50% | 2-4 |
The Psychology of Catch Rates
Game Freak designed the catch system with specific psychological principles:
- Variable Ratio Reinforcement: The unpredictable number of shakes creates a gambling-like excitement
- Near-Miss Effect: Three shakes followed by a breakout makes players feel “almost” succeeded
- Sunk Cost Fallacy: The longer a battle takes, the more attached players become to catching the Pokémon
- Achievement Unlock: Rare catches provide significant dopamine releases
Understanding these principles can help players manage frustration during difficult captures and appreciate the design behind the mechanics.
Programming the Catch Rate Algorithm
For developers interested in implementing this system, here’s a pseudocode representation of the Generation 7 catch algorithm:
function calculateCatchRate(pokemon, ball, status, hpCurrent, hpMax, turns, isCritical, isShiny, environment) {
// Base values
const baseRate = pokemon.catchRate;
const ballBonus = getBallBonus(ball, pokemon, environment);
const statusBonus = getStatusBonus(status);
const catchPower = getCatchPowerBonus();
const shinyBonus = isShiny ? 1.5 : 1;
const criticalBonus = isCritical ? 2 : 1;
// Modified catch rate calculation
let modifiedRate = Math.floor((3 * hpMax * baseRate * ballBonus * statusBonus * catchPower * shinyBonus) / (3 * hpCurrent));
// Apply critical catch bonus to first shake only
const firstShakeRate = Math.min(255, modifiedRate * criticalBonus);
const secondShakeRate = Math.floor((modifiedRate * 1048560) / 65536) / 255;
const thirdShakeRate = Math.floor((secondShakeRate * 1048560) / 65536) / 255;
// Probability calculations
const firstShakeProb = firstShakeRate / 255;
const secondShakeProb = secondShakeRate / 255;
const thirdShakeProb = thirdShakeRate / 255;
return {
modifiedRate: modifiedRate,
firstShakeProb: firstShakeProb,
secondShakeProb: secondShakeProb,
thirdShakeProb: thirdShakeProb,
overallProb: firstShakeProb * secondShakeProb * thirdShakeProb
};
}
function getBallBonus(ball, pokemon, environment) {
// Implementation would include all ball type logic
// ...
}
Historical Evolution of Catch Mechanics
The catch rate system has evolved significantly across Pokémon generations:
- Gen 1-2: Simple formula with only HP and ball type factors
- Gen 3: Introduced status condition modifiers
- Gen 4: Added critical catch mechanic (HP ≤ 1/3)
- Gen 5: Introduced shake count display and modified ball multipliers
- Gen 6: Added new ball types (Dusk, Net, etc.) with type-based bonuses
- Gen 7: Introduced Catch Power, Ultra Beasts, and Beast Ball mechanics
- Gen 8+: Further refined with Dynamax raids and new ball types
The Ultra Sun system represents the most complex iteration before the Dynamax mechanics of Sword/Shield, offering a perfect balance between accessibility for casual players and depth for competitive collectors.