Free Bet Value Calculator
What a stake-not-returned free bet is actually worth, and the lay odds that turn it into guaranteed cash.
£14.0770.3% of face value
- Lay stake
- £14.35
- Lay liability
- £45.93
- If back wins
- +£14.07
- If lay wins
- +£14.07
- Retention
- 70.3%
Retention across back odds
With a stake-not-returned free bet, retention rises with the back odds — reaching about 87% by odds 12.0 — provided you can still lay near the back price. Very long odds mean the free bet usually returns nothing before you lay it.
A free bet is almost never worth its face value. With a "stake not returned" (SNR) token you only ever collect the winnings, not the stake, so a £20 free bet at even money returns £20, not £40. Its real worth depends entirely on the odds you use it at and what you do with it.
If you lay the same selection on an exchange, you can convert the free bet into cash that is yours whichever way the event goes. The lay stake is the free bet times the back odds minus one, divided by the lay odds minus the commission. Done at close prices this typically retains 70–80% of the token's face value, and the retention rises as you use higher back odds — up to a point where the lay side gets too expensive.
If you simply place the free bet and hope, its expected value is your win probability times the potential winnings. At fair odds that works out to (odds − 1) / odds of the face value — about two-thirds at odds of 3.0 — but with real variance attached.
FAQ
- What back odds should I use a free bet at?
- For lay-off conversion, somewhere around 3.0 to 6.0 usually maximises retention: high enough that the free winnings are large relative to the stake you are not getting back, but not so high that the lay liability eats the gain. The calculator's slider shows the curve for your exact numbers.
- Why is retention not 100%?
- Because you never get the free bet stake back, and because laying costs the exchange's commission plus a small spread. Both are unavoidable frictions, so some value is always lost in the conversion.
- Is using a free bet at very high odds a good idea?
- For raw expected value it can be, but the outcome is almost always nothing. Lay-off conversion trades that lottery for a smaller, certain amount — which is why matched bettors prefer it.