Poisson Calculator
Calculate probabilities for sports betting props based on historical averages
Exactly 3.5
0.00%
(0% outcome)
At Least 3.5
0.00%
At Most 3.5
0.00%
The Poisson Calculator is designed to estimate the probability of a certain outcome occurring in a game, based on historical averages. This is especially useful for player props where individual stats are involved. The calculator assumes events happen independently and at a constant average rate — which often fits well for things like 3-pointers, goals, or strikeouts.
For example, if Steph Curry averages 4.1 made 3-pointers per game, you can use the Poisson Calculator to estimate the probability of him making 6 or more threes in an upcoming game. If a sportsbook offers over 5.5 threes at +350 odds, and the calculator suggests fair odds should be +300, you know the bet offers positive expected value because you're getting a better price than the true probability suggests.
Tip: The Poisson Calculator works best when you have a solid average for the stat you're analyzing. The more accurate your inputs, the better your edge in spotting profitable props.
Frequently Asked Questions
The Poisson Calculator is a tool used by bettors to estimate the probability of a specific outcome occurring based on historical averages. It’s commonly used for player props like 3-pointers, strikeouts, or goals scored.
The Poisson distribution models the likelihood of a certain number of events happening over a fixed period, assuming each event happens independently. In sports, it helps estimate the chance of a player or team achieving a certain stat based on their average performance.
You need two inputs: the player or team’s average (mean) performance and the target outcome you want to calculate the probability for. For example, if a player averages 2.7 made 3-pointers per game, enter 2.7 as the average.
Use it when you want to estimate the probability of player props or other discrete events, and compare that probability to the sportsbook odds to identify positive expected value bets.
Fair odds are the odds that directly reflect the calculated probability from the Poisson distribution. If your calculated probability is 28.6%, then the fair odds would be +250.
Yes, you can apply the Poisson distribution to team totals as well — such as total goals, runs, or points — as long as the assumption of independent events is reasonable.
Yes, Poisson assumes independent, evenly distributed events, which may not perfectly reflect real-life scenarios where factors like player fatigue, game pace, and matchup quality affect outcomes. Always combine Poisson with other handicapping methods.