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Pokémon One-Hit KO (OHKO) Chance Calculator

Determine the probability of knocking out an opponent in a single hit. Factor in Attack/Sp. Atk stats, move power, type effectiveness, and the 16 possible damage rolls.

Interpreting Your Result

A 100% OHKO chance means you should attack immediately. A 0% chance means you should consider a different move or a setup turn (like Swords Dance).

✓ Do's

  • Use entry hazards like Stealth Rock to "soften" targets into OHKO ranges.
  • Target an opponent's weaker defensive stat (e.g., use Special moves against a high-Defense/low-Sp. Def Pokémon).
  • Layer your modifiers: weather (Rain/Sun), STAB, and items like Life Orb can stack for massive damage.
  • Check for the "Sturdy" ability or "Focus Sash", which prevent OHKOs regardless of damage.

✗ Don'ts

  • Don't rely on a 6.25% OHKO chance as your primary win condition; it's essentially a "miracle" roll.
  • Don't ignore the target's possible held items (like Shuca Berry) that could halve your damage.
  • Don't forget about "Intimidate" or "Snarl", which can drop your offensive stats before you strike.
  • Don't assume a high-base power move like "Overheat" is always better than "Flamethrower" if both secure the same OHKO chance.

How It Works

The Pokémon One-Hit KO (OHKO) Chance Calculator is a vital tool for offensive strategy. It tells you exactly how likely you are to secure a knockout with your next move. Whether you are checking if your Choice Band Garchomp can OHKO a standard Blissey or if your Kyogre’s Water Spout is enough to sweep, this tool uses the core damage formula to provide a percentage chance based on the 16 random damage rolls in the game engine.

Formula Used

OHKO Chance % = (Number of damage rolls >= Target HP) / 16 * 100%. Damage is calculated using the official Pokémon formula with modifiers for type, items, and weather.

Real Calculation Examples

  • 1A Close Combat from a Lucario (252 Atk) vs. a Steelix (252 HP) resulting in a 43.8% OHKO chance.
  • 2Using Choice Specs to turn a 0% OHKO chance into a guaranteed 100% OHKO.
  • 3Calculating how Stealth Rock damage (12.5% HP) can turn a 2HKO into a high-probability OHKO.

Related Calculators

The Comprehensive Guide

Pokémon OHKO Chance Calculator: Quantifying Offensive Power

Every competitive Pokémon player knows the rush of seeing an opponent's HP bar drop to zero in a single hit. But behind that flash of light is a complex mathematical formula. The Pokémon OHKO Chance Calculator is your gateway to understanding these odds and building teams that force progress through overwhelming force.

This guide explains the mechanics of the One-Hit KO (OHKO), the 16 random damage rolls, and how you can manipulate the math to ensure your sweepers never leave a target with 1% HP.

What Exactly is an OHKO?

An OHKO occurs when a single damaging move reduces the target's HP from 100% to 0%. While players often talk about "OHKO moves" (like Fissure or Sheer Cold), in competitive play, the term usually refers to high-damage attacks like Close Combat, Behemoth Blade, or Water Spout that deal enough raw damage to surpass the opponent's bulk.

The Mathematic of "The Range"

In Pokémon, damage is not static. For every attack, there are 16 possible damage values. These values are determined by taking the maximum possible damage (the "100% roll") and multiplying it by factors ranging from 0.85 to 1.00.

The OHKO Probability Calculation

If your target has 200 HP, the calculator checks all 16 rolls:

  • - If only the 100% roll is ≥ 200: 6.25% Chance
  • - If the 93% through 100% rolls are ≥ 200: 50% Chance
  • - If the 85% roll is ≥ 200: Guaranteed (100%) OHKO

Comparison Table: Offensive Benchmarks (Level 50 VGC)

Understanding these numbers is easier when looking at the "Titans" of the current meta. Here is how some common offensive threats perform using the Pokémon OHKO Chance Calculator.

Attacker Target Move OHKO Chance
Zacian-C (Atk+)Sylveon (252 HP)Behemoth Blade100%
Urshifu-RIncineroar (252 HP)Close Combat68.8%
Kyogre (Specs)Groudon (Standard)Water Spout (Full)100%
Landorus-TRillaboom (Assault Vest)Max Airstream31.3%

How to Manipulate the OHKO Chance

1. The Chip Damage Strategy

The easiest way to turn a low OHKO chance into a guaranteed one is through Entry Hazards. Stealth Rock deals between 3.125% and 50% damage depending on type effectiveness. For most neutral targets (12.5% damage), this is enough to shift the OHKO probability from "low roll" to "guaranteed".

2. Stacking Multipliers

The damage formula is multiplicative. This means small boosts become massive when layered.
Example: A move with STAB (1.5x) AND a Life Orb (1.3x) AND a Helping Hand boost (1.5x) deals nearly 3 times its base damage. This is how "Nukes" like Dracovish or Regieleki were able to OHKO even resistant targets.

3. Physical vs. Special Split

Optimizing for an OHKO often means attacking the opponent's "weak side". If you are facing a Blissey (Base 10 Def / Base 135 Sp. Def), even a weak physical move has a much higher OHKO probability than a powerful special move. The Pokémon OHKO Chance Calculator helps you identify these structural weaknesses in an opponent's team.

Most Searched OHKO Calculations

  • "What is the highest possible damage in Pokémon?" - Currently involves a Choice Banded, Help Handed, Power Spoted Shuckle using Rollout against a Combee.
  • "Does critical hit guarantee an OHKO?" - Not always. A crit is a 1.5x multiplier. If the move originally dealt 40% damage, a crit only brings it to 60%, still failing the OHKO.
  • "How much Atk is needed to OHKO Incineroar?" - Depends on Intimidate. Most players aim for a 100% OHKO after one Intimidate drop.

The Legend of the "1% Survival"

There is nothing more frustrating than an opponent living with a sliver of health. Often, this is due to the Focus Sash or Sturdy ability. However, if they live without those mechanics, it means your move hit a "Low Roll". By using the Pokémon OHKO Chance Calculator during team building, you can adjust your EV spreads—perhaps taking away a few points from Speed—to ensure that the "1% survival" never happens again.

The Role of Terrain and Weather

Don't forget the environment!

  • Electric/Psychic/Grassy Terrain: Boost moves of that type by 1.3x.
  • Rain/Sun: Boost Water/Fire moves by 1.5x and weaken the opposing type by 0.5x.
A Kyogre in the sun has its OHKO chance against a Steel-type significantly reduced, while in the rain, it becomes a "guaranteed" delete button.

Conclusion: Offense is a Numbers Game

High-level Pokémon is about reducing variance. While you can't control which of the 16 rolls the game picks, you can control the math that surrounds them. Use the Pokémon One-Hit KO Chance Calculator to audit your team. If your primary win condition relies on a 50% OHKO range, consider adding Stealth Rock or switching to a Choice item to secure that 100%. Master the range, and master the match.

Frequently Asked Questions

Usage of This Calculator

Who Should Use This?

Aggressive Pokémon offensive players, sweeper-builders, and anyone looking to optimize their damage benchmarks.

Limitations

Does not account for evasion or accuracy. Assumes the move hits. Also does not factor in critical hits, which add a separate layer of probability.

Real-World Examples

The Close Combat Sweep

Scenario: A Lucario is facing a Tyranitar. It needs to know if Close Combat will OHKO.

Outcome: The calculator shows a 100% chance due to 4x weakness. The player clicks the move without hesitation.

The Hydro Pump Gamble

Scenario: A Rotom-W wants to OHKO a Landorus-T in rain.

Outcome: Calculation shows an 81.3% OHKO chance (13/16 rolls). The player decides the risk is worth it.

Summary

The ultimate offensive tool. Know your power, find your range, and secure the knockout. The Pokémon OHKO Chance Calculator turns guessing into winning.