Flip a Coin 100 Times
Press once and this page runs 100 coin flips, then shows the full sequence, the heads and tails tally, the longest run, and a results string you can copy straight into a homework table. Counts go up to 10000.
What you get back
- The sequence in order, so flip 43 is still flip 43 and not just part of a total.
- The tally: how many heads, how many tails.
- The longest run of the same face, and where it started.
- A copyable results string. Paste it into a document, a spreadsheet column or a homework table as real text rather than retyping a hundred letters.
What to expect from 100 flips
Fifty is the average, not the promise. The count of heads follows the binomial distribution with n = 100 and p = 0.5, and the numbers below come straight out of it.
| Result | Chance in 100 fair flips |
|---|---|
| Exactly 50 heads | about 8% |
| Between 45 and 55 heads | about 73% |
| Between 40 and 60 heads | about 96.5% |
The standard deviation is the square root of 100 multiplied by 0.5 multiplied by 0.5, which comes out at exactly 5. That single number explains the table: one deviation either side of fifty is 45 to 55, two is 40 to 60. Landing on exactly fifty is the single most likely outcome and still happens less than one run in ten, which is the point most people get wrong.
Long runs are normal
A streak feels like the coin is broken. It is not. In a hundred fair flips:
- A run of six or more of the same face appears about 81% of the time.
- A run of seven or more appears about 54% of the time.
- A run of eight or more appears about 32% of the time.
- A run of ten or more still appears about 9% of the time.
So the more surprising outcome is a hundred flips with no run of six in them.
The generator, honestly
These flips come from your browser’s random number generator, not from a physical coin. It has no memory: eight tails in a row does not make heads more likely on the ninth flip, and nothing in the sequence is due. The page assumes an exact 50/50 coin. A real coin thrown by a real hand is not guaranteed to be exactly that, but this simulator does not model any of it.
Because it is pseudorandom, two people who press the button will get different sequences. If a teacher asks the whole class to flip a hundred times, that is the point: the spread of the class results is the lesson, not any one student’s fifty-three.
Other counting tools
If you need a grid of numbers rather than a sequence, times table 1 to 100 is copyable in the same way. Press the button 100 times counts and times your own clicks, and the rest of the hundred-times tools are on copy and paste 100 times.