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Coin Flip Probability

Probability of N heads in M coin flips.

Probability of exactly 7 heads in 10 flips
11.72%
1 in 9

P(at least 7 heads): 17.19%

P(at most 7 heads): 94.53%

P(all heads): 0.10%

P(no heads): 0.10%

Binomial probability for coin flips (or any independent yes/no trials). Set P(heads) below 0.5 for a biased coin or above for the lucky one. Useful for understanding how likely a streak really is.

About

Enter total flips, target heads count, and probability per flip. The tool computes binomial probability for exact, at-least, and at-most outcomes plus all-heads / no-heads extremes.

How to use

  1. Enter flips and heads.

FAQ

Why is my streak unlikely but happens anyway?+

Even unlikely things happen given enough trials. The probability of 10 heads in a row is 0.098%, but if you flip 10,000 sets of 10 coins, it'll happen ~10 times.