Pokemon Catch Rate Calculator

Understanding the Catch Rate Formula

Every Pokemon in the mainline games has a base catch rate between 3 and 255. Common Pokemon like Caterpie and Magikarp sit at 255, while box legendaries like Mewtwo and Rayquaza are down at 3. This number feeds into a formula that determines how likely you are to catch the Pokemon on any given throw.

The formula takes four inputs: the Pokemon's base catch rate, the ball multiplier, the status condition multiplier, and the ratio of current HP to max HP. From these, it calculates a modified catch rate (called "a" in the formula), then converts that into a shake check probability. The game rolls four random numbers, and all four need to pass for the catch to succeed.

Why HP Matters So Much

The HP component in the formula is (3 x MaxHP - 2 x CurrentHP) divided by (3 x MaxHP). When current HP is at maximum, this fraction equals 1/3. When current HP is at 1, the fraction is nearly 1. That means dropping a Pokemon to 1 HP gives you roughly 3x better odds than throwing at full health. This is why False Swipe is one of the most important moves for catching Pokemon. It always leaves the target at 1 HP.

Best Strategy for Legendaries

Legendary Pokemon with a catch rate of 3 are some of the hardest catches in the game. Here is the optimal approach:

Start the battle by throwing a Quick Ball on turn 1. With a 5x multiplier, this gives you a small but real chance of ending the fight immediately. If that misses, use False Swipe to drop the legendary to 1 HP, then inflict Sleep with a move like Spore or Hypnosis. From here, switch to Timer Balls and keep throwing. By turn 10, Timer Balls reach their maximum 4x multiplier. With 1 HP and Sleep, each Timer Ball throw gives roughly a 13-14% chance against a catch rate 3 Pokemon, so you should catch it within 15-20 throws on average.

If you are playing at night or inside a cave, Dusk Balls with their 3x multiplier are a strong alternative in the early turns before Timer Balls overtake them.

Specialty Balls and When to Use Them

Net Balls give 3.5x on Water and Bug types, which makes them better than Ultra Balls for those types. Fast Balls give 4x on Pokemon with a base Speed of 100 or higher, like Charizard, Gengar, or Greninja. Love Balls give a massive 8x multiplier when used on the same species with opposite gender, but this is situational.

Beast Balls are a special case. They give 5x on Ultra Beasts but only 0.1x on everything else, making them terrible for normal catches. Heavy Balls work best on heavy Pokemon like Snorlax, Steelix, and Groudon, adding a flat bonus to the catch rate instead of a multiplier.

Critical Capture

Critical capture was added in Generation V. When a critical capture triggers, the ball only needs to pass one shake check instead of four. This means your effective catch probability jumps significantly. The chance of a critical capture depends on how many Pokemon you have caught in your Pokedex. At 600 or more caught, you get the maximum multiplier. This is another reason to catch everything you see, not just the Pokemon you want to use in battle.

Catch Rates by Generation

The catch rate formula has stayed mostly the same since Generation V, with minor adjustments in each new game. Sword and Shield introduced guaranteed catches for certain story battles, like Eternatus. Legends: Arceus used a completely different system based on throwing Poke Balls in the overworld. Scarlet and Violet went back to the traditional formula. This calculator uses the standard Gen V+ formula, which covers Black/White, X/Y, Sun/Moon, Sword/Shield, and Scarlet/Violet.