Catch Rate Calculator

An advanced tool to determine your exact capture probability.

What is a Catch Rate Calculator?

A catch rate calculator is a specialized tool used by Pokémon trainers to determine the probability of successfully capturing a wild Pokémon. The chance of a catch isn’t random; it’s governed by a complex mathematical formula that takes several factors into account. By inputting variables like the Pokémon’s health, its intrinsic catch rate, the type of Poké Ball used, and any status conditions, this calculator reverse-engineers the game’s mechanics to give you a precise percentage of success for each throw. This tool is invaluable for anyone serious about completing their Pokédex, especially when hunting for rare or legendary Pokémon, where every Poké Ball counts.

The Pokémon Catch Rate Formula and Explanation

The core of this catch rate calculator is the capture formula used in most modern Pokémon games (from Generation V onwards). The process involves calculating two main values, which we’ll call ‘a’ and ‘b’.

First, the modified catch rate ‘a’ is calculated:

a = ( (3 * MaxHP - 2 * CurrentHP) * BaseRate * BallBonus * StatusBonus ) / (3 * MaxHP)

This value ‘a’ represents an adjusted catch rate based on the current battle situation. If ‘a’ is 255 or greater, the catch is guaranteed. If not, this value is used to determine the probability of the Poké Ball shaking, which is value ‘b’.

b = 65536 / (255 / a)^(0.1875)

The game performs four “shake checks.” For a capture to be successful, the ball must pass all four checks. The probability of passing a single shake check is `b / 65536`. Therefore, the final probability of a successful capture is:

P = (b / 65536) ^ 4

Formula Variables

Variable	Meaning	Unit	Typical Range
MaxHP	The Pokémon’s maximum health points.	HP (Points)	10 – 700+
CurrentHP	The Pokémon’s current health points.	HP (Points)	1 – MaxHP
BaseRate	The Pokémon’s species-specific catch rate.	Unitless	3 – 255
BallBonus	The multiplier from the Poké Ball used.	Multiplier (x)	1x – 255x
StatusBonus	The multiplier from a status condition.	Multiplier (x)	1x – 2.5x

Practical Examples

Example 1: Catching a Healthy Pikachu

Imagine you encounter a healthy Pikachu and want to know your odds with a standard Poké Ball.

• Inputs: Max HP: 110, Current HP: 110, Base Rate: 190, Ball Bonus: 1x, Status: None.
• Results: The calculator shows a catch chance of around 24.7% per ball. While not terrible, you can see how it might take a few tries. For tips on your hunt, you could consult a legendary pokémon locations guide for general strategies.

Example 2: Catching a Weakened, Sleeping Snorlax

Now, let’s try a tougher target, a Snorlax, but this time we’ve prepared.

• Inputs: Max HP: 250, Current HP: 10, Base Rate: 25, Ball Bonus: 2x (Ultra Ball), Status: Asleep (2.5x).
• Results: The probability jumps to approximately 15.6% per ball. Despite Snorlax’s low base rate, lowering its HP and inflicting sleep makes a huge difference. This shows the importance of strategy, much like when preparing for effort values training.

How to Use This Catch Rate Calculator

1. Enter HP Values: Input the target Pokémon’s maximum and current HP. Using a move like False Swipe to get Current HP to 1 is a great strategy.
2. Set Base Catch Rate: Find the Pokémon’s base rate online (Bulbapedia and Serebii are great resources). Common Pokémon are around 190-255, while legends are often at 3.
3. Select Your Ball: Choose the Poké Ball you’re using from the dropdown. Notice how a Quick Ball on the first turn or a Dusk Ball at night offers a huge advantage.
4. Add Status Condition: If the Pokémon is asleep, frozen, paralyzed, etc., select the condition. Sleep and Freeze provide the biggest boost.
5. Interpret the Results: The calculator will instantly show your percentage chance to catch the Pokémon with a single ball. It also shows intermediate values from the formula and the cumulative chance of catching it within five throws. Check out our IV calculator to assess your Pokémon after the catch!

Key Factors That Affect Catch Rate

• Pokémon’s HP: The lower the Pokémon’s current HP relative to its max HP, the higher the catch rate. This is the most direct factor you can influence in battle.
• Base Catch Rate: This is an unchangeable, species-specific value. A Caterpie (255) is inherently easier to catch than a Mewtwo (3).
• Poké Ball Type: Don’t just throw Poké Balls! Using the right ball for the situation (e.g., Net Ball for a Bug-type, Quick Ball on turn one) provides a massive multiplier.
• Status Conditions: Inflicting Sleep or Freeze gives a 2.5x bonus, making it one of the most effective strategies for catching tough opponents. Paralysis, Burn, and Poison offer a still-valuable 1.5x bonus.
• Pokémon’s Level (for Nest Ball): The Nest Ball is unique in that its effectiveness increases the lower the target’s level is compared to your own Pokémon.
• Turn Count (for Timer Ball): The Timer Ball becomes more effective as more turns pass in the battle, making it ideal for long, drawn-out fights against defensive Pokémon. Thinking about your team for these long fights is also key; perhaps a team builder could help.

Frequently Asked Questions (FAQ)

Is a catch ever 100% guaranteed without a Master Ball?

Yes. If the modified catch rate ‘a’ in the formula is 255 or higher, the catch is guaranteed. This can happen with very high base rate Pokémon (like Caterpie or Pidgey) even at full health with a regular Poké Ball.

Why is False Swipe so popular for catching Pokémon?

False Swipe is a move that will never reduce a Pokémon’s HP below 1. Since the catch formula heavily rewards low current HP, guaranteeing the Pokémon is at its lowest possible health point provides the maximum possible bonus from HP reduction.

Does the Pokémon’s level matter?

Directly, no (with one exception). The catch formula uses HP, not level. However, higher-level Pokémon tend to have higher Max HP, making it harder to get their HP to a low percentage. The exception is the Nest Ball, which is more effective on lower-leveled Pokémon.

Which status condition is the best for catching?

Sleep and Freeze are equally the best, providing a 2.5x bonus to the catch rate. Paralyze, Burn, and Poison are next, with a 1.5x bonus. Since Freeze is often temporary and harder to inflict, Sleep is generally the most reliable and effective status for captures.

Why does the calculator use a Gen V+ formula?

The formula was slightly different in earlier generations. We use the most recent and widely applicable formula to provide a modern, accurate tool for current players. The core principles (low HP, status, better balls) remain the same across all generations.

How does the calculator handle a Master Ball?

The Master Ball has a functional ball bonus of 255. When this is put into the formula, the resulting ‘a’ value is almost always over 255, leading to a guaranteed catch and a 100% probability. Some events, like those discussed on our Pokémon GO community day blog, might have special catch mechanics.

What is the ‘Shake Check’?

After you throw a ball, the game essentially “rolls a die” four times. Each roll is a shake check. You need to pass all four checks to catch the Pokémon. The ‘Shake Check Probability’ shows the chance of passing one of these checks. The final catch chance is this probability to the power of 4.

Can I increase my odds of finding rare Pokémon?

While this tool helps you catch them, finding them is another challenge. Methods like using items with the “Lure” effect, chaining encounters, and understanding spawn mechanics are key. For specific odds, a shiny hunting odds calculator can be very useful.