AI football analysis calculator: value, odds and Kelly stake
Enter the odds and your own probability estimate — the calculator does the rest: implied probability from the price, the betting edge, a recommended stake from the Kelly criterion, and the margin the bookmaker baked into its 1 X 2 odds. None of our numbers go into the maths; every input is yours.
Betting value
Enter the odds and your own probability estimate. The bankroll is optional — it only converts the Kelly fraction into a stake.
Enter odds greater than 1 and a probability between 0 and 100. The result appears on its own.
Bookmaker margin
Enter the home, draw and away prices from one match at one bookmaker.
Enter all three prices, each greater than 1.
Everything is computed in your browser. Nothing is sent anywhere, nothing is stored, and none of our data enters the calculation.
What this calculator is, and what it is not
It is plain arithmetic over your own numbers. It uses none of our predictions, sends nothing anywhere and remembers nothing. Which is exactly why its output is only as good as the probability estimate you feed it.
The formulas behind the calculator
None of this is secret and none of it is complicated. Here is every calculation with a worked example, so you can check the output on paper.
Implied probability
implied probability = 100 / oddsDecimal odds are an inverted probability — the one the bookmaker is pricing, plus its margin. This number tells you how often the outcome would have to land for the bet to break even over the long run.
Odds of 2.50 → 100 / 2.50 = 40%. At that price the outcome has to happen at least 40% of the time before you stop losing money.
Betting edge (value)
edge = (your probability × odds − 1) × 100Edge holds your estimate against the price. A positive number means you rate the outcome more likely than the odds do. A negative one means the market is more cautious than you are.
A 45% estimate at odds of 2.50 → 0.45 × 2.50 = 1.125 → edge +12.5%. At a 38% estimate: 0.38 × 2.50 = 0.95 → edge −5%.
Kelly criterion
f = (odds × your probability − 1) / (odds − 1)Kelly says what fraction of the bankroll to stake so that it grows as fast as possible over time. The formula assumes your probability estimate is accurate — which is its single biggest weakness, and why half of the number is used far more often than the whole of it.
Odds 2.50, estimate 45% → (2.50 × 0.45 − 1) / 1.50 = 0.125 / 1.50 = 0.0833, i.e. 8.33% of the bankroll. On a €500 bankroll that is €41.67, and half Kelly is €20.83.
Bookmaker margin
margin = (1/odds1 + 1/oddsX + 1/odds2 − 1) × 100The implied probabilities of all three outcomes always add up to more than 100%. That surplus is the margin — the price you pay for the bet regardless of how the match ends.
Odds of 2.10 / 3.40 / 3.60 → 0.4762 + 0.2941 + 0.2778 = 1.0481 → a margin of 4.81%.
The numbers in these examples illustrate the maths. They are not our predictions and not our results — current aggregate figures live on the homepage in the Statistics section.
This calculator vs the one inside a Tipsport betslip
A bookmaker has its own calculator right in the slip, but it answers a different question: how much you win if the pick lands. That is not the same as value. You can work out a payout in your head; you cannot work out value without a probability estimate. The table compares what each tool does — and Tipsport wins three of the rows.
| Feature | Futbaldata | Tipsport |
|---|---|---|
| Betting edge calculated from your own probability estimate | ||
| Recommended stake size from the Kelly criterion | ||
| Bookmaker margin computed from the 1 X 2 odds | ||
| Independent probability estimate from an in-house model | ||
| Potential payout calculated inside the betslip | ||
| Live odds available inside the tool itself | ||
| Ability to place the bet and get paid out |
Why the calculator alone is not enough
This page exists so you can run the numbers yourself, right now. It would be dishonest to pretend that settles the question. The calculator is division. The hard part is the number you type into it.
1. Everything hangs on a single estimate
At odds of 2.50 the break-even line sits at exactly 40%. Estimate 45% and the calculator shows +12.5%, which looks like an obvious bet. If the true probability is 38%, the same sum is really −5%. Seven percentage points flip the verdict completely — and the calculator has no way of knowing.
2. Kelly amplifies estimation error, it does not absorb it
The Kelly formula assumes your number is right. If you systematically overrate your own picks by a few points, Kelly will not say "you are staking too much" — it will compute a bigger stake. That is why half Kelly is the common recommendation: not because it is mathematically superior, but because it dampens the error.
3. Margin tells you about the bookmaker, not the match
A low margin means a fairer price, but says nothing about who wins. It is a useful filter for deciding where to place a bet — not a basis for choosing which bet to place.
4. Estimating the probability is the whole job
Arriving at a number better than the price means processing form in context, head-to-head history, absences, weather and the fixture schedule — and doing it the same way for every match, not just the one you fancy. That is exactly what our model does. The calculator on this page stays free and signup-free; if you want a probability to put into it, see how the model works one out.
In short: the calculator tells you whether a bet is worth placing given your estimate. It cannot tell you whether the estimate is any good.
Let the model handle the probability
One complete AI match analysis every day, free and without registration — including an explicit probability you can drop straight into the calculator above.
Frequently Asked Questions
Is the calculator free, and do I need an account?
It is free and needs no account. Everything runs in your browser, so the odds and bankroll you type are never sent anywhere and never stored.
Where does the calculator get the probability from?
Nowhere — you supply it. No data or predictions of ours enter the calculation by design; it is plain arithmetic over your numbers. If you have no estimate of your own, read today’s free AI match analysis, where the probability is spelled out.
What is edge, and how much of it makes a bet worthwhile?
Edge is the gap between your estimate and what the odds already price in. A positive edge means you rate the outcome more likely than the market does. Because the whole figure rests on your estimate, most bettors only act on an edge large enough to survive a normal estimation error, rather than anything barely above zero.
Should I stake the full Kelly fraction?
Full Kelly is optimal only if your probability estimate is exact. In practice it never is, which is why the calculator also shows half Kelly. Halving the stake cuts bankroll swings sharply and makes an inaccurate estimate hurt far less.
What counts as a normal margin?
It depends on the competition and the bookmaker — top leagues tend to be tighter, fringe competitions wider. The useful way to read it is comparatively: compute the margin on the same match at several bookmakers and place the bet where it is lowest.
Why is the calculator showing me nothing?
Odds have to be greater than 1 and the probability has to sit between 0 and 100. The margin calculator needs all three prices filled in. If an input is empty or out of range the result simply does not appear — nothing breaks and nothing is flagged.
Related pages
- How AI calculates football predictions
- Football predictions and how they are made
- Football statistics that actually mean something
- Correct score tips
Warning: Gambling is prohibited for persons under 18 years of age. Play responsibly. Futbaldata does not operate a bookmaker and is not responsible for your betting decisions. This calculator is an informational tool, not a recommendation to bet.