- Maths reviewed by Josh Miller
- Tested by Diana Westfield
A total goals calculator turns one number, how many goals you expect in a match, into the chance of every over/under line. Put in each side’s expected goals, pick the line (2.5 is the one everyone bets), and you get the chance of over and under, the fair odds for each, and, from the bookmaker’s prices you type in, whether either side is worth backing and how much margin the book is taking.
Total goals betting in one example
Home side 1.55 expected goals, visitors 1.15: 2.7 in total, about what a mid-table Premier League game gives you. The CasinoCalcs calculator puts over 2.5 at 50.6% and under at 49.4%, fair odds of roughly 1.97 and 2.03. A bookmaker offering 1.85 and 1.95 is taking about 5.3% margin, and neither side is value at those numbers. At 2.10 for the over you’d be looking at a 6% edge, if your expected goals are right. That “if” is doing all the work.
Over/under lines at a glance
| Expected goals | Over 1.5 | Over 2.5 | Over 3.5 |
|---|---|---|---|
| 2.0 | 59.4% | 32.3% | 14.3% |
| 2.5 | 71.3% | 45.6% | 24.2% |
| 2.8 | 76.9% | 53.1% | 30.8% |
| 3.2 | 82.9% | 62.0% | 39.7% |
Notice how steep it is around 2.5. Moving from 2.5 to 2.8 expected goals shifts over 2.5 by seven and a half points, which is the difference between a fair price of 2.19 and 1.88. Get your goal expectation slightly wrong and you’ll see “value” everywhere.
Where the numbers come from
The calculator uses a Poisson distribution, the standard first model for football goals. It’s good, but it has a known lean: real matches finish 0-0 and 1-1 a little more often than Poisson expects, so unders close to the line are slightly underrated by it. The Poisson calculator gives each team’s goals separately, the correct score calculator builds the full grid of scores, and both teams to score is the natural partner market. To check the margin on any two-way price, try the bookmaker margin calculator.
If you have expected goals for each team, the over under calculator adds team totals, and the 1X2 calculator gives the match result.
A good model is still just a model. BeGambleAware.org has free help if betting is costing more than you planned.