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Critical Hit Chance Calculator

GamingDamage and Combat Stats

The crit chance shown on your character sheet.

200% means a crit deals double damage.

Chance of at least one crit —
Expected number of crits
—
Average damage multiplier per hit
—
Hits for a 50% chance of a crit
—
Hits for a 90% chance of a crit
—

With a crit chance p, the chance of at least one critical hit in n attacks is 1 − (1 − p)^n. At 25% over 10 hits that is 1 − 0.75^10 = 94.4%, with 2.5 crits expected. With 200% crit damage, each hit averages 1.25 times normal damage.

About this tool

Crit chance on a character sheet is a per-hit number, but fights are decided over many swings. This calculator turns that single percentage into the odds that matter during a fight: the chance of seeing at least one crit over a burst, the number of crits to expect, and how many attacks it takes before a crit becomes a coin flip or a near-certainty. Add your crit damage and it also gives the average multiplier crits add to every hit, which is the figure to compare when choosing between crit chance and crit damage gear. A table lists the chance of landing exactly 0, 1, 2 and up to 10 crits. The model assumes every hit rolls independently at the same chance; games with pseudo-random distribution, crit streak protection or guaranteed crits after a miss streak will differ.

How to use it

  1. Set your crit chance

    Drag the slider or type the exact percentage, such as 16.67 or 42.5.

  2. Enter the number of hits

    Use the attacks in one burst, one boss phase, or one full fight.

  3. Add crit damage

    Enter what a crit deals relative to a normal hit; 200% is double damage.

  4. Read the odds and the table

    Check the headline chance, the hits needed for 50% and 90%, and the exact-count table.

Examples

1-in-6 crit chance over 4 attacks

Critical hit chance
16.6667
Number of hits or attacks
4
Crit damage (of a normal hit)
200

Result Chance of at least one crit: 51.8%
Expected number of crits: 0.67
Average damage multiplier per hit: 1.167
Hits for a 50% chance of a crit: 4
Hits for a 90% chance of a crit: 13

  1. Chance of no crit in 4 hits = (1 − 0.1667)^4 = 0.4823
  2. At least one crit = 1 − 0.4823 = 51.77%
  3. Expected crits = 4 × 0.1667 = 0.667
  4. Average damage factor = 1 + 0.1667 × (2 − 1) = 1.1667

A 16.67% crit chance behaves like rolling a six on a die: four swings give a crit just over half the time.

25% crit, 10 hits, 200% crit damage

Critical hit chance
25
Number of hits or attacks
10
Crit damage (of a normal hit)
200

Result Chance of at least one crit: 94.4%
Expected number of crits: 2.5
Average damage multiplier per hit: 1.25
Hits for a 50% chance of a crit: 3
Hits for a 90% chance of a crit: 9

  1. Chance of no crit in 10 hits = (1 − 0.25)^10 = 0.0563
  2. At least one crit = 1 − 0.0563 = 94.37%
  3. Expected crits = 10 × 0.25 = 2.5
  4. Average damage factor = 1 + 0.25 × (2 − 1) = 1.25

You expect 2.5 crits and almost always see at least one; on average every hit is worth 1.25 normal hits.

How it is calculated

P(at least one) = 1 − (1 − p)^n; E[crits] = n × p; multiplier = 1 + p × (m − 1)

p
crit chance per hit, as a fraction (25% = 0.25)
n
number of independent hits
m
crit damage as a multiple of a normal hit (200% = 2)

Each hit is treated as an independent trial, so crit counts follow a binomial distribution. The chance of no crit is (1 − p)^n, and its complement is the chance of at least one. The exact count k has probability C(n,k) p^k (1 − p)^(n−k). Hits needed for a target chance t come from n = ln(1 − t) ÷ ln(1 − p), rounded up.

When not to use it

  • Games using pseudo-random crits, such as Dota 2, raise the chance after each miss, so these odds are off.
  • Damage that is capped, overkilled or reduced by armour after the crit needs a full damage model.
  • Crit chance above 100% that converts into extra damage is a game-specific rule this does not apply.

Common mistakes

  • Adding the crit chance per hit, as if 25% over four hits made a crit certain.
  • Entering crit damage as the bonus only, such as 50% instead of 150% total.
  • Comparing gear by crit chance alone while ignoring the average damage multiplier.

Frequently asked questions

Why is four hits at 25% not a guaranteed crit?

Each hit rolls separately, so the chances do not add up. The chance of missing all four is 0.75^4 = 31.6%, which leaves 68.4% for at least one crit. Even 20 hits at 25% still leave a 0.3% chance of no crit at all.

How do crit chance and crit damage combine?

The average damage per hit is a normal hit times 1 + p × (m − 1). At 30% chance and 250% damage that is 1 + 0.3 × 1.5 = 1.45, so crits add 45% to sustained damage. The multiplier column lets you compare two gear options directly.

Is 50% crit chance worth more than 100% extra crit damage?

It depends on your current numbers. Raising chance by Δp adds Δp × (m − 1) to the multiplier, while raising damage by Δm adds p × Δm. When chance times damage is balanced, the cheaper stat to raise is usually the one you have less of.

What does the hits for 50% and 90% figure mean?

It is the smallest number of attacks after which the chance of at least one crit reaches that level. At 10% crit chance you need 7 hits for a 50% chance and 22 hits for 90%.

Does this work for a 1-in-20 natural 20 in tabletop games?

Yes. Enter 5% for a natural 20 on a d20, or 10% if your character crits on 19 or 20. The rolls are independent, so the binomial model fits dice exactly.

Why does the table stop at 10 crits?

Beyond ten crits the individual probabilities are small and the list would grow long for large hit counts. The cumulative column on the last row still tells you how much probability is left for more than ten crits.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 16). Critical Hit Chance Calculator. Tools Directory. Retrieved October 25, 2026, from https://tools.milunir.com/gaming/damage-and-combat-stats/critical-hit-chance-calculator/

MLA

Tools Directory Editorial Team. “Critical Hit Chance Calculator.” Tools Directory, 16 Oct. 2026, https://tools.milunir.com/gaming/damage-and-combat-stats/critical-hit-chance-calculator/. Accessed 25 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Critical Hit Chance Calculator.” Tools Directory. Last modified October 16, 2026. Accessed October 25, 2026. https://tools.milunir.com/gaming/damage-and-combat-stats/critical-hit-chance-calculator/.

Link<a href="https://tools.milunir.com/gaming/damage-and-combat-stats/critical-hit-chance-calculator/">Critical Hit Chance Calculator – Tools Directory</a>