Coin Flip Probability Calculator
Find the odds of getting a number of heads in n flips.
The odds of the flips
Flip a fair coin several times and the chance of a specific number of heads follows the binomial distribution. Getting exactly seven heads in ten flips is less likely than intuition suggests.
The probability of exactly 7 heads in 10 flips is about 11.7%, while the chance of at least 7 is around 17.2%. Enter your own counts to see the odds.
Exact and private
The calculation runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
How is it computed?
With the binomial formula for a fair coin: the number of ways to get k heads, times one-half to the power of the number of flips.
What does it show?
The chance of exactly k heads, and the chance of at least k heads.
Is the coin fair?
Yes, this assumes a fair coin with a 50% chance each flip.
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