Estimate what a free bet is worth
Enter the free bet amount and the odds you would play: the tool works out its average value, stake not returned.
Result
- Return if the free bet wins (stake not returned)
- 20.00
- Implied probability
- 33.33%
- Estimated no-margin probability
- 31.45%
- Overround applied
- +6.00%
- Expected value
- 6.29
- Expected value as % of the amount
- 62.89%
Warning:
Expected value, not winnings: any single free bet pays its net winnings or nothing. The no-margin probability comes from removing the overround proportionally. No odds are recommended.
The tool calculates the expected value of a stake-not-returned free bet: no-vig estimated probability × amount × (odds − 1). The no-vig probability comes from an overround you enter (6% by default) or, if you fill them in, from the odds of the other outcomes in the market. An expected value is never a win: a given free bet returns its net profit or nothing.
How does this calculator work?
The tool works out the net profit of a free bet if it wins, then multiplies it by the estimated probability of winning once the margin is removed: that is the expected value. Everything is calculated in the browser, as you type.
The result is labelled "expected value", never "winnings". It describes what a free bet is worth on average, not what it will return.
The formulas used
Three formulas are enough.
return if it wins = amount × (odds − 1)
no-vig estimated probability = (1 ÷ odds) ÷ (1 + overround)
expected value = no-vig estimated probability × return if it wins
When you enter the odds of the other outcomes, the second formula is replaced by the normalised probability of the chosen outcome over the full market, and the overround shown becomes the market's own, measured as on the margin calculator.
A full worked example
A €10 free bet at odds of 3.00, with a 6% overround, returns €20.00 if it wins. Its implied probability is 33.33%, or 31.45% once the margin is removed.
Its expected value comes to €6.29, or 62.89% of its face value. These are the figures the tool shows when it opens: they serve as a consistency check against the table on the free bets page.
What the result does not tell you
The expected value recommends no odds. It rises with the odds, but so does the probability of getting nothing: at 10.00, a free bet loses about nine times out of ten. Nor does it account for the offer's terms (minimum odds, wagering requirements, expiry), which often reduce its real value.
For how to read implied probability and the bookmaker margin, the dedicated pages cover each notion in detail.
Frequently asked questions
Is this tool free to use, with no account?
Yes. The calculation runs in the browser, with no account, no data sent and no record of the amounts or odds you enter.
Is the expected value what I will win?
No. It is an average over a large number of identical free bets. A given free bet returns either its net profit or nothing at all. The higher the odds, the more often it returns nothing.
Why does the return if it wins not include the stake?
Because a free bet is almost always stake not returned: the operator credits the net profit, amount × (odds − 1), but not the amount given. It is the most common rule, to be checked in the terms of each offer.
What are the odds of the other outcomes for?
To measure the market's real overround rather than assume it. On a 1X2 market, enter the odds you would take, then the other two odds: the tool removes the margin by proportional normalisation, like the margin calculator.
Can this tool be used to convert a free bet into cash?
No. It calculates no hedging stake with another operator and teaches no conversion method. It measures the value of a free bet as it stands, to show why its face value is misleading.
Can I enter numbers with a comma?
Yes. Comma and dot are accepted interchangeably: 3,00 as well as 3.00. To separate the odds of the other outcomes, use a space or a semicolon.
Sources & methodology
This calculator applies the model for valuing a stake-not-returned free bet described in the academic literature, and the proportional normalisation of probabilities documented on the no-vig odds page.
- Return if it wins = amount × (odds − 1): the stake given is not returned.
- No-vig estimated probability = implied probability ÷ (1 + overround), or the probability normalised over the full market if the other odds are entered.
- Expected value = no-vig estimated probability × return if it wins; also shown as a percentage of the free bet amount.