Free tool
Matched betting calculator.
The arithmetic behind matched betting: the lay stake on the exchange that offsets a bookmaker back bet, and the qualifying loss or locked free-bet value it leaves. Information, not advice.
The lock is only as good as the execution. The figure holds if both bets are placed correctly at these odds before either settles. Odds move, bookmakers limit and restrict accounts, and a mistake breaks the match. This is arithmetic and information — not advice, not a promise of profit, and 18+ only.
The worked example
A £10 free bet at 6.0, laid at 6.2 with 5% commission: lay stake = £10 × 5 ÷ (6.2 − 0.05) = £8.13, liability £42.28. If the bookmaker bet wins you keep £50 − £42.28 = £7.72; if it loses, the lay wins £8.13 × 0.95 = £7.72. Either way you retain £7.72 — about 77% of the free bet's face value.
Straight answers
How does a matched betting calculator work?
It works out the lay stake on the exchange that best offsets a back bet at the bookmaker, so the outcome is the same whichever result lands. For a qualifying bet that leaves a small, known 'qualifying loss'; for a free bet it leaves a locked profit, because the free stake costs you nothing.
What is the lay stake formula for matched betting?
For a qualifying (stake-returned) bet, lay stake = (back stake × back odds) ÷ (lay odds − commission). For a free bet where the stake is not returned, lay stake = (back stake × (back odds − 1)) ÷ (lay odds − commission).
Is matched betting risk-free?
The maths locks the outcome only if you place both bets correctly, at the odds you enter, before either settles. Real risk comes from mistakes, odds moving, bookmaker limits and account restrictions. This tool does the arithmetic; it does not remove those risks, and it is information, not advice.
How much is a free bet worth when laid off?
Typically 70–85% of the free-bet stake, depending on the back and lay odds and the commission. Closer odds and lower commission retain more. Enter your numbers to see the exact retained value.
Locking a free bet is arithmetic. Getting both legs down before the price moves is the skill.
The Sports Trading OS manual — £47 Or practise free on the ladder trainerTrading with a plan already? The Evaluation Programme is the funded-trader path — £29/mo, cancel any time.
18+ · Education, not betting advice · No tips, no picks · BeGambleAware.org
More free tools: back/lay hedge · lay stake & liability · commission · all calculators