Gen 7 Catch Rate Calculator

For Pokémon Sun, Moon, Ultra Sun, and Ultra Moon

Overall Chance to Catch

–%

Shake Probability: –%

Modified Rate (a): —

Shake Check (b): —

Catch Probability Breakdown

This chart visualizes the probability of the Pokémon staying in the ball after each shake. The final bar represents the overall catch probability.

What is a gen 7 catch rate calculator?

A gen 7 catch rate calculator is a specialized tool for players of Pokémon Sun, Moon, Ultra Sun, and Ultra Moon to determine their precise chances of capturing a wild Pokémon. Unlike a generic percentage calculator, it uses the specific mathematical formula hardcoded into the Generation 7 games. This formula considers multiple variables, including the Pokémon’s species-specific catch rate, its current and maximum HP, the type of Poké Ball used, any active status conditions, and in the case of USUM, Roto Catch powers. Using a gen 7 catch rate calculator empowers trainers to optimize their strategy, save valuable Poké Balls, and understand why some Pokémon are significantly harder to catch than others.

The Gen 7 Catch Rate Formula and Explanation

The core of this gen 7 catch rate calculator is the official capture formula from the games. The process involves two main steps: calculating a ‘modified catch rate’ (let’s call it a), and then using that to determine the probability of passing four ‘shake checks’.

Step 1: The Modified Catch Rate (a)

a = ( ( (3 * HP_max - 2 * HP_current) * catch_rate * ball_bonus ) / (3 * HP_max) ) * status_bonus * roto_catch

This formula first determines a base value modified by the Pokémon’s remaining health. The lower the health, the higher this value. It’s then multiplied by various bonuses. If this value ‘a’ is 255 or higher, the capture is guaranteed.

Variables in the Gen 7 Catch Formula

Variable	Meaning	Unit / Type	Typical Range
HP_max	The target Pokémon’s maximum health points.	Number	10 – 300+
HP_current	The target Pokémon’s current health points.	Number	1 – HP_max
catch_rate	The Pokémon species’ base capture rate.	Number	3 – 255
ball_bonus	The multiplier from the Poké Ball being used.	Multiplier (e.g., 1x, 2x)	0.1x – 255x
status_bonus	The multiplier for a status condition.	Multiplier (1x, 1.5x, 2.5x)	1x for none, 2.5x for Sleep/Freeze
roto_catch	Multiplier from Roto Catch power (USUM only).	Multiplier (1x or 2x)	Applies a 2x bonus if active.

Step 2: The Shake Check Value (b) and Final Probability

b = 1048560 / sqrt(sqrt(16711680 / a))

The game then calculates a second value, b. For a Pokémon to be caught, it must pass four successful “shake checks.” The probability of passing a single shake is b / 65535. The overall chance of capture is this probability raised to the power of 4.

Catch Probability = (b / 65535) ^ 4

For more detailed information, you can check out resources like the Bulbapedia catch rate page. This tool simplifies that complex math for you.

Practical Examples

Understanding the theory is one thing, but seeing it in action makes it clear. Here are two scenarios using our gen 7 catch rate calculator.

Example 1: Catching an Early-Game Grubbin

• Inputs:
  • Pokémon Catch Rate: 255 (Grubbin)
  • Max HP: 20
  • Current HP: 1 (after False Swipe)
  • Ball: Poké Ball (1x bonus)
  • Status: None (1x bonus)
• Results:
  • Overall Catch Chance: ~44.5%
  • With a simple Poké Ball at 1 HP, you still have less than a 50/50 chance. If you induced Paralysis (1.5x bonus), the chance would jump to ~58.8%, making the catch much more likely. For even better results, consult a list of all Poké Ball effects.

Example 2: Attempting to Catch Tapu Koko

• Inputs:
  • Pokémon Catch Rate: 3 (Tapu Koko)
  • Max HP: 150
  • Current HP: 1 (after False Swipe)
  • Ball: Ultra Ball (2x bonus)
  • Status: Asleep (2.5x bonus)
• Results:
  • Overall Catch Chance: ~5.2%
  • Even under ideal conditions—1 HP, asleep, and using an Ultra Ball—catching a legendary Pokémon is a significant challenge. This low percentage is why trainers often spend dozens of turns and balls. Using a Timer Ball after 10 turns (4x bonus) would increase this to ~8.2%, a notable improvement. This highlights the importance of using a gen 7 catch rate calculator to find your best strategy.

How to Use This Gen 7 Catch Rate Calculator

1. Enter Base Catch Rate: Find the Pokémon’s base catch rate online (a quick search for “[Pokémon Name] catch rate” works). Common Pokémon are high (255), while legendaries are very low (3).
2. Input HP Values: Enter the Pokémon’s maximum HP and its current HP. For best results, use the move False Swipe to get the Pokémon to exactly 1 HP.
3. Select Your Ball: Choose the Poké Ball you’re using from the dropdown menu. The calculator will apply the correct multiplier.
4. Add Status Condition: If the Pokémon is asleep, frozen, paralyzed, burned, or poisoned, select the appropriate condition to apply the bonus.
5. Add Roto Catch: If playing Ultra Sun/Ultra Moon and a Roto Catch is active, select it for a powerful 2x boost.
6. Analyze the Results: The calculator instantly shows your percentage chance to catch the Pokémon per ball, along with intermediate values from the formula. Use this data to decide if you should switch to a better ball or spend more turns setting up. For further reading, see this guide on capturing Pokémon.

Key Factors That Affect Gen 7 Catch Rate

• Base Catch Rate: This is the single most important factor. A Pokémon with a rate of 255 (like Caterpie) is vastly easier to catch than one with a rate of 3 (like Necrozma).
• Remaining HP: The lower the Pokémon’s HP relative to its max, the higher the catch chance. This is why moves like False Swipe are invaluable.
• Status Conditions: Applying a status condition is one of the best ways to improve your odds. Sleep and Freeze provide the best bonus (2.5x) in Gen 7.
• Poké Ball Type: Different balls have different multipliers. Using the right ball for the situation (e.g., Dusk Ball at night, Quick Ball on turn 1) dramatically increases your chances.
• Roto Catch (USUM): This is a powerful, game-specific boost in Ultra Sun and Ultra Moon that doubles your final modified rate, making it a massive advantage.
• Beast Balls and Ultra Beasts: Beast Balls have a huge 5x multiplier on Ultra Beasts but a tiny 0.1x multiplier on any other Pokémon, making them highly specialized. Our gen 7 catch rate calculator accounts for this unique interaction.

Frequently Asked Questions (FAQ)

• Why is my catch chance 0%?

  This usually happens if an invalid number is entered (like Current HP being greater than Max HP) or a specific mechanic is at play, like trying to catch a high-weight Pokémon with a Heavy Ball under certain conditions (though that’s a Gen 2/4 mechanic, the principle applies to edge cases). Double-check your inputs.

• Is a Master Ball always 100%?

  Yes. The Master Ball bypasses the formula entirely by having a multiplier of 255, which guarantees the ‘a’ value is high enough for an automatic capture. The only exceptions are specific in-game encounters where a Pokémon cannot be caught by any means.

• What’s the difference between this and a gen 6 calculator?

  The formulas are very similar, but Gen 7 introduced Roto Catch powers and adjusted the multipliers for some balls like the Quick Ball (from 4x to 5x on turn 1). This gen 7 catch rate calculator is specifically tailored for those changes.

• Does leveling up my Pokémon increase the catch rate?

  Not directly, unless you are using a Level Ball. However, higher-level Pokémon can learn moves like False Swipe and Spore, and have more HP to survive attacks while you try to catch the target.

• Is False Swipe the best move for catching?

  It’s one of the best. It guarantees the target will have 1 HP, which maximizes the health-based part of the formula. Combining it with a move that causes Sleep or Paralysis is the ultimate catching strategy.

• Why does the calculator show “unitless” values?

  The core values in the catch rate formula (HP, base rate) are numbers that are plugged into a specific mathematical equation. They don’t represent a physical unit like kilograms or meters, but rather abstract game-defined values. The result is a probability, expressed as a percentage.

• How accurate is this calculator?

  This tool is based on the reverse-engineered and publicly documented catch rate formula for Pokémon Generation 7. Assuming the inputs are correct, the resulting probability is as accurate as possible, matching what happens inside the game.

• Does the ‘Beast Ball’ work on normal Pokémon?

  Technically yes, but it’s a terrible idea. It has a multiplier of 0.1x on non-Ultra Beasts, making it 10 times *worse* than a standard Poké Ball. It’s designed specifically for catching Ultra Beasts, where it has a 5x multiplier.