Enter the face value of the free bet, the back odds at the bookmaker, the lay odds on the exchange and your commission rate. The calculator returns the lay stake, the liability it ties up and the cash you keep whichever side wins. A £50 free bet converted at 5.00 and 5.20 leaves around £37.84.
Why a Free Bet Is Worth Less Than Its Face Value
Almost every bookmaker free bet is stake not returned. Win at 5.00 with a £50 token and you collect £200 of profit while the £50 itself stays with the bookmaker. The token is worth only what you can pull out of it.
Conversion works by backing an outcome with the token and laying the same outcome for cash on an exchange. One of the two bets wins, and the lay stake is sized so both paths land on the same figure. That figure is the locked-in amount, and it sits in a balance you can withdraw.
A Worked Example
A £50 free bet, stake not returned, backed at 5.00 and laid at 5.20 with 2% exchange commission.
- Lay stake: (5.00 – 1) × 50 ÷ (5.20 – 0.02) = £38.61.
- Liability held by the exchange: £162.16.
- Bookmaker bet wins: £37.84 retained.
- Exchange lay wins: £37.84 retained.
- Conversion rate: roughly 76% of face value.
The two outcome lines matching is the whole point of the calculation. Whether the 5.00 shot wins or loses, £37.84 ends up in one account or the other.
How to Read the Results
Lay stake is the figure you type into the exchange. Miss it in either direction and you are left carrying the result instead of converting it.
Liability is the cash the exchange freezes while the market is live: £162.16 against a £38.61 lay stake. Converting at long odds ties up far more than the token is worth, so your exchange balance, rather than the offer calendar, usually decides how many conversions you can run at once.
Retained profit reads the same on both lines by design. Two different figures means the lay stake does not match the prices you entered, or the commission field is wrong for your account.
Conversion rate turns cash into a percentage of face value, which is the number to compare across offers. 76% of a £50 token is £37.84. The same rate on a £10 token is worth much less in absolute terms, and the work involved is identical.
Where the Conversion Rate Slips
Commission rates vary. The example uses 2%; some exchanges charge up to 5% and some run 0% promotions on selected markets. Every point of commission comes straight out of the retained figure, so check your own account rate before trusting a default.
The back-to-lay gap does the rest of the damage. 5.00 against 5.20 is a 0.20 spread. Longer odds usually retain more of a stake-not-returned token, and they also come with wider spreads and thinner exchange liquidity, so the two effects pull against each other. Enter several candidate pairs and let the retained figure decide rather than reaching for the longest price on the board.
Three things the calculator cannot see: whether the exchange has enough money in the market to match £38.61 at 5.20, whether the bookmaker will void the bet on a term you skipped, and whether the account is about to be restricted. Free bets also expire, often within seven days, and an unused token converts at 0%.
Conversion is arithmetic rather than forecasting, so there is nothing here for a model to sharpen. The Matched Betting Calculator handles the step before this one, where a qualifying bet unlocks the token. The Back and Lay Calculator prices the exchange side of any single bet, and the Hedge Calculator runs the same lay-stake maths on a bet you have already placed with your own money.
Further Reading
- All betting calculators: the full library of 34 free tools
- Orbit Exchange review: professional exchange betting through a broker
- Glossary: the terms you will see across Gecko Edge
How much is a £50 free bet worth in cash?
Roughly £37.84 at the prices in the worked example, which is about 76% of face value. Backing at 5.00 and laying at 5.20 with 2% commission needs a lay stake of £38.61 and leaves the same £37.84 whichever bet wins. Tighter back-to-lay gaps push retention higher; wider ones and higher commission pull it down.
What does stake not returned mean?
A stake-not-returned free bet pays only the profit portion if it wins. A £50 token at 5.00 returns £200 rather than £250, because the bookmaker keeps the token itself. This is why conversion favours longer odds: the higher the price, the larger the profit portion relative to the face value you can never get back.
What odds are best for converting a free bet?
Longer odds retain a bigger share of a stake-not-returned token, and they carry wider back-to-lay spreads and thinner exchange liquidity, so the gain has a ceiling. The example converts at 5.00 back and 5.20 lay for roughly 76%. Enter a few candidate pairs and compare the retained figures rather than assuming the longest price available is the best one.
Can I convert a free bet without a betting exchange?
You can lay off at a second bookmaker by backing the opposing outcomes, though retention is usually lower because bookmaker margins are wider than exchange commission. You also carry the risk of one side being voided while the other stands. An exchange gives you a single opposing price and a known commission rate, which is why most conversions run through one.