Convert a free bet into cash
This free bet conversion calculator shows what a bonus bet is worth, the lay stake that guarantees it, and the retention rate. Results update as you type.
Formula and worked example
Free bet profit = free bet value x (back odds - 1)
Lay stake = free bet profit / (lay odds - commission)
Guaranteed profit = lay stake x (1 - commission)
Retention = guaranteed profit / free bet value
A 50 free bet at 5.00 wins 200 if it lands, because a stake-not-returned token pays winnings only. Laying the same selection at 5.20 on an exchange charging 2% needs a lay stake of 200 / (5.20 - 0.02) = 38.61, with a liability of 162.16.
Whichever way the selection goes, you finish about 37.84 up, which is 75.7% of the token's face value. That percentage is the retention rate, and it is the number worth comparing between offers.
Why longer odds retain more
A stake-not-returned free bet pays only the winnings, so the shorter the price, the less of the token you extract. At 2.00 you are converting 50 into roughly 50 of profit before the lay; at 5.00 you are converting it into 200.
Retention rises with the back price, which is why free bets are usually used at longer odds than the same person would back with their own money. The limit is the gap between back and lay: the wider it is, the more the lay costs you.
Reading the result
Liability is what the exchange holds while the bet is open, and it is far larger than the lay stake. Check that the balance is there before placing the back leg.
Retention below about 70% usually means the back and lay prices are too far apart, and waiting for a closer match is normally worth more than the offer's deadline pressure. Terms vary between operators; read them before relying on any figure here.
Limits and responsible use
The no-vig split is a proportional estimate. It does not model information, bias or execution risk. Settlement and void rules can also change the realised result. See Gambling Commission LCCP 4.2.6.
Set a spending limit before gambling and do not chase losses. Read GambleAware's advice and our responsible gambling guidance.
Related tools and guides
After comparing prices, you can compare betting partners. Oddly Likely may earn a commission from partner links; check current odds, eligibility and terms. Read the affiliate disclosure.
Frequently asked questions
What is a no-vig calculator?
A no-vig calculator removes the bookmaker's margin from a market. Fair probability = implied probability divided by the total market probability. Convert that fair probability back to a price and you have the no-vig, or fair, odds.
How do you remove the vig from odds?
Convert every price in the market to an implied probability, add them together, then divide each one by that total so they sum to 100%. A -110 / -110 market implies 52.4% and 52.4%, which totals 104.8%. Dividing each by 104.8% gives 50% and 50%, or +100 / +100 in moneyline terms.
What is a normal hold percentage?
On a two-way moneyline, roughly 4% to 5% is standard, and sharper books run nearer 2%. Three-way football markets usually carry more because there are three prices to pad. The hold is the amount by which the market's implied probabilities exceed 100%.
Why are fair odds different from the odds I can bet?
Fair odds are what the market implies once the margin is stripped out. No bookmaker offers them, because the margin is how the book makes money. Fair odds are a reference point for judging whether a price you can actually bet is generous or short.
Does this work for three-way markets?
Yes. This calculator handles two to six outcomes, so a football market with home, draw and away devigs correctly. Most no-vig calculators only accept two outcomes because American sports rarely have a draw.
Do no-vig odds mean a bet is good?
No. Removing the margin tells you what the market believes once the book's cut is taken out. It does not tell you whether the market is right. A price that beats the fair odds is only value if your own view of the probability is better than the market's.
Frequently asked questions
How do you calculate free bet conversion?
Free bet profit = value x (back odds - 1), because a stake-not-returned token pays winnings only. Lay stake = that profit / (lay odds - commission). Guaranteed profit = lay stake x (1 - commission), and retention is guaranteed profit divided by the face value.
What is a good free bet retention rate?
Roughly 70% to 80% is normal on a stake-not-returned token. Below about 70% usually means the back and lay prices are too far apart, and waiting for a closer match is generally worth more than rushing the offer.
Why use a free bet at high odds?
Because the token pays only the winnings. At 2.00 a $50 free bet is worth $50 before any lay; at 5.00 it is worth $200. Retention rises with the back price, limited by how wide the gap to the lay price gets.
What is the difference between stake returned and stake not returned?
A stake-returned bonus pays winnings plus the stake, so it is worth roughly its face value more. Almost every free bet token is stake not returned, which is what this calculator assumes.
How much liability do I need?
Liability is lay stake x (lay odds - 1), and it is far larger than the lay stake itself. A $38.61 lay at 5.20 ties up $162.16 at the exchange. Check the balance is there before placing the back leg.
Sources
- Gambling Commission, LCCP condition 4.2.6. Current code accessed 30 July 2026.
- GambleAware, Advice to consider if you're gambling. Accessed 30 July 2026.