Probabilities and fair odds
Correct score
Home goals down the side, away goals across the top. Tap a score for its fair odds.
A Poisson calculator turns one simple idea into a full set of football prices: if you know how many goals each team should score on average, you can work out the chance of every scoreline. Enter expected goals for both sides, or let the free calculator above work them out from each team’s season averages, and you’ll see home, draw and away chances, over/under lines, both teams to score and a correct score grid.
The example has the home side on 1.6 expected goals and the visitors on 1.1. Home win comes out at 49%, the most likely score is 1-1 at 12%, and 1-0 is close behind at 11%.
Poisson calculator: how it gets from goals to odds
Goals in football are rare, random events, and that’s exactly what the Poisson distribution describes. With an average of 1.6, a team scores no goals about 20% of the time, one goal 32%, two goals 26%, and so on. Do the same for the away side, multiply the two together for every score, and you have the correct score grid.
Add up the right cells and you get everything else. Every cell where the home side has more goals is a home win. Every cell totalling three or more is over 2.5 goals. Fair odds are just 1 divided by the chance.
Where the expected goals come from
The “From team averages” tab uses the standard approach. Take the home side’s goals per home game and divide by the league average to get an attack strength. Do the same with the away side’s goals conceded on the road for a defence weakness. Multiply them together, then by the league’s average home goals. Repeat the other way round for the away team.
So a home side scoring 1.8 a game in a league that averages 1.5, against visitors who concede 1.5 away from home, gets an expected 1.80 goals. If you have proper expected goals (xG) figures from a stats site, use those directly instead.
Using the numbers
Compare the fair odds with the bookmaker’s. If the model says 1-1 is fair at 8.45 and you can get 9.00, that’s a bet the model likes. Keep in mind what it leaves out. Basic Poisson treats the two teams’ goals as independent, so it tends to underrate draws, especially 0-0 and 1-1, and it knows nothing about injuries, motivation or the weather. Treat it as a starting price, not the final word.
The bookmaker margin calculator strips the margin out of a bookie’s prices so you can compare like with like. For two-way handicap lines, the Asian handicap calculator settles every result.
A model gives you a view, not a certainty. Football will always surprise it. BeGambleAware.org is free and confidential if it stops being fun.