PokéBase - Pokémon Q&A

# Is there a way to calculate catch rate into percentage?

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in bulbapedia it shows catch rate and percentage.

1 vote

## Yes

I assume you're already well aware of how the modified Catch Rate is calculated;

Where a is the modified Catch Rate.

Now, how do we convert this to an actual % chance? To answer that, the games have another mathematical algorithm, referring Shake Probability and Shake Checks which determines the final percentage. The algorithm for Shake Probability is this as of Gen VI;
b = 65536 / (255/a)^0.1875

So what is a Shake Check? Basically, a random number is generated in between 0 and 65535. That number is compared to your b value, which is your shake probability. If your b value is smaller or equal to the random number generated, than your Shake Check fails, and you DO NOT catch the Pokemon. 4 Shake Checks are performed, and if you pass all 4 then the Pokemon is caught. If your a value is 255 or greater, than the shake checks are automatically bypassed and it is an immediate capture (this is why the rumor about Master Ball having a chance to fail is actually a myth).

After finding your b value, if you wish to calculate the % yourself, you can use general probability mathematics to do so. If you haven't learnt how to do this, then just go for a quick Google and I'm sure you'll find some calculators for chance of a capture.