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Impostor Odds Calculator Logic
Why a Crewmate Streak Doesn't Change Your Next-Game Odds
The most common misconception I see repeated in Among Us communities is treating a long crewmate streak as meaning an impostor round is somehow "due." If you have been crewmate five games running in a 10-player, 2-impostor lobby, your odds in game six are still exactly 20%, unchanged by the streak. Among Us assigns roles independently at the start of every single game, with no memory of what happened in previous rounds.
This is a textbook instance of the gambler's fallacy, the same reasoning error that leads people to bet on red after a long run of black at a roulette wheel. The multi-game mode on this calculator makes the distinction concrete: it shows the probability of a specific number of impostor rounds across a set of games using binomial probability, which is a genuinely different question from "am I due" and does not imply any individual future game is more or less likely to hand you the role.
What the Impostor Odds Calculator Actually Does
This calculator works out your exact probability of being assigned Impostor in a single Among Us lobby, using the straightforward relationship: impostor odds equal the number of impostors divided by the number of players, expressed as a percentage. According to Inverse's coverage of the original impostor odds tool, this simple calculation became popular within the Among Us community precisely because the base game gives no in-lobby indication of your odds before roles are assigned.
Players use the single-game mode to check their odds before a match starts, and the multi-game mode to answer a genuinely different question: given a set number of games, what is the probability of landing impostor a specific number of times, at least that many times, or at most that many times. That second calculation requires binomial probability, not simple division, since it accounts for every possible combination of outcomes across the games played.
The Odds Formula and Common Lobby Configurations
The formula is impostor probability equals impostors divided by players, multiplied by 100. A standard 10-player lobby with 2 impostors gives each player a 20% chance; the same lobby size with 3 impostors, common in larger custom games, raises that to 30%. A smaller 7-player lobby with a single impostor gives each player roughly 14.3%.
| Players | Impostors | Odds per Player |
|---|---|---|
| 10 | 1 | 10.0% |
| 10 | 2 | 20.0% |
| 10 | 3 | 30.0% |
| 7 | 1 | 14.3% |
| 5 | 1 | 20.0% |
| 15 | 3 | 20.0% |
Notice that lobby size and impostor count trade off against each other: a 5-player lobby with 1 impostor gives the same 20% odds as a 10-player lobby with 2 impostors, since it is the ratio that determines individual probability, not either number alone.
How Multi-Game Binomial Probability Works
Across multiple games, the probability of landing impostor exactly k times in n games follows the binomial distribution: the number of ways to choose which k games were impostor rounds, multiplied by the per-game impostor probability raised to the k, multiplied by the per-game crewmate probability raised to the remaining games. The Gamepressure explainer on impostor odds covers the same binomial approach used by the original popular impostor odds tools.
The "at least" and "at most" modes sum this exact-probability calculation across a range of outcomes rather than a single value, answering questions like "what are the odds I get impostor at least twice in the next 10 games" rather than "exactly twice." These cumulative modes are usually more useful in practice, since most players care about a threshold (at least once, at most twice) rather than an exact count.
Accuracy and Limitations
This calculator's probability math is exact for the player count, impostor count, and game count entered, assuming Among Us assigns roles with a uniform random distribution across eligible players, which is the documented behaviour of the base game's role assignment. It does not account for custom mods, host-controlled role assignment tools, or any third-party plugin that overrides the default random selection, all of which can change the actual odds from what uniform randomness would predict.
The calculator also treats every game as fully independent, which matches how Among Us actually assigns roles. If you suspect a specific lobby or host is not assigning roles randomly, no probability calculator can detect that from the outside; it can only tell you what the odds should be under fair, independent role assignment.