Coin Flip
Heads or tails, with a running count.
Heads: 0 · Tails: 0
A fair flip
Each flip is an independent 50/50 result. The coin has no memory, so after five heads in a row the next flip is still exactly as likely to be heads as tails. Feeling that tails is "due" is a common mistake known as the gambler’s fallacy. The tally shows how results even out over many flips without any single flip being influenced by the last.
How many heads in 10 flips?
| Heads | Chance |
|---|---|
| 0 | 0.10% |
| 1 | 0.98% |
| 2 | 4.4% |
| 3 | 11.7% |
| 4 | 20.5% |
| 5 | 24.6% |
| 6 | 20.5% |
| 7 | 11.7% |
| 8 | 4.4% |
| 9 | 0.98% |
| 10 | 0.10% |
Exactly five heads, the "expected" result, happens less than a quarter of the time. Getting 6 and 4 or 7 and 3 is completely normal.
Chance of a streak starting with the next flip
| Heads in a row | Chance | About 1 in |
|---|---|---|
| 2 | 25.0% | 4 |
| 3 | 12.5% | 8 |
| 4 | 6.3% | 16 |
| 5 | 3.1% | 32 |
| 6 | 1.6% | 64 |
| 8 | 0.39% | 256 |
| 10 | 0.10% | 1,024 |
Real coins
Physical coin tosses are very slightly biased toward landing on the side that started facing up. A large 2023 study of over 350,000 tosses put it at about 51%. A virtual flip has no starting side, so it is an even 50/50.
When to flip a coin
For deciding who goes first, settling a tie, or breaking a deadlock between two equally good options. For more than two options, use the decision wheel, and for games that need numbers, the dice roller.