Matched betting turns bookmaker sign-up offers and free bets into an almost risk-free profit. You back an outcome at a bookmaker and lay the same outcome (bet against it) at a betting exchange. Whatever happens, one bet wins and the other loses, so the result is nearly the same either way. With a qualifying bet you lose a small amount to unlock the offer; with the free bet itself you keep most of its value.
Everything depends on the lay stake. Too small and you lose if the back bet loses; too large and you lose if it wins. The balanced stake equalises the two outcomes after the exchange’s commission on winnings (typically 2–5%). For a “stake not returned” free bet only the winnings count, so the lay stake is smaller and the profit is usually 70–85% of the free bet’s face value; for a “stake returned” free bet the stake is paid out too.
Enter the stake, the back and lay odds in decimal form and the commissions. The lay odds should be close to the back odds – the closer they are, the less a qualifying bet costs and the more a free bet returns.
How to use the Matched Betting Calculator
- Bet type
- Back stake
- Back odds (decimal)
- Bookmaker commission on winnings (usually 0)
- Lay odds (decimal)
- Exchange commission
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
The calculator works out what the back bet pays if it wins (after any bookmaker commission), then solves for the lay stake that makes the profit equal whether the exchange or the bookmaker bet wins. Liability is what you need in the exchange account to place the lay.
Worked example
Stake 10 at back odds 11, lay odds 11.5, exchange commission 2%. Qualifying bet: lay stake = 10 × 11 ÷ (11.5 − 0.02) = 9.58, liability 9.58 × 10.5 = 100.61; either way you lose 0.61. Free bet (SNR): lay stake = 100 ÷ 11.48 = 8.71 and you keep 8.71 × 0.98 = 8.54 whichever bet wins – 85% of the free bet. Stake-returned free bet: lay 9.58 and profit 9.39.
Responsible gambling
Matched betting removes the gamble only when both bets are placed correctly at the odds shown. Check the odds before each bet, never chase losses and seek help from a support service if betting stops being under control.
Inputs explained
| Field | What to enter |
|---|---|
| Bet type | Choose one: Qualifying bet (your own money), Free bet – stake not returned (SNR), Free bet – stake returned (SR) |
| Back stake | Amount in your currency |
| Back odds (decimal) | A number |
| Bookmaker commission on winnings (usually 0) | In % |
| Lay odds (decimal) | A number |
| Exchange commission | In % |
What each result means
- Liability (needed in the exchange) = [Lay stake]×([Lay odds (decimal)] – 1)
- Result as a share of the stake (retention for free bets) = min([Profit if the bookmaker bet wins], [Profit if the exchange (lay) bet wins])÷[Back stake]×100
Example values
How the main result changes when Back stake changes and everything else stays at the example values above:
| Back stake | Lay stake |
|---|---|
| 5 | 4.79 |
| 7.5 | 7.19 |
| 10 | 9.58 |
| 12.5 | 11.98 |
| 15 | 14.37 |
| 20 | 19.16 |
Formula
Net back win W = stake × (back odds − 1) × (1 − bookmaker commission) · Lay stake = (W + stake) ÷ (lay odds − exchange commission) for qualifying and stake-returned bets, W ÷ (lay odds − commission) for stake-not-returned free bets · Liability = lay stake × (lay odds − 1)
Worked example
Inputs — Bet type: Qualifying bet (your own money); Back stake: $10; Back odds (decimal): 11; Bookmaker commission on winnings (usually 0): 0 %; Lay odds (decimal): 11.5; Exchange commission: 2 %.
Results — Lay stake = $9.58; Liability (needed in the exchange) = $100.61; Profit if the bookmaker bet wins = $-0.61; Profit if the exchange (lay) bet wins = $-0.61; Result as a share of the stake (retention for free bets) = -6.1 %; Assessment = Expensive qualifying bet – look for closer odds.
Key terms
- Back bet
- A bet that an outcome will happen, placed at a bookmaker.
- Lay bet
- A bet that an outcome will not happen, placed at an exchange; you act as the bookmaker.
- Liability
- The maximum you can lose on a lay bet.
- Retention
- The share of a free bet's face value that you lock in as profit.
Frequently asked questions
What is matched betting?
Backing an outcome at a bookmaker and laying it at an exchange so that the result is the same either way, used to extract value from free bets and sign-up offers.
Is matched betting legal?
Yes in the UK and many other countries – it is just placing ordinary bets. Bookmakers may restrict accounts that only take offers. In the UK, betting winnings are not taxed for private individuals.
Why do I lose money on a qualifying bet?
Lay odds are usually slightly higher than back odds and the exchange takes commission, so a qualifying bet typically costs a few percent of the stake – about 0.61 on a 10 stake in our example.
Why are higher odds better for free bets?
With a stake-not-returned free bet only the winnings are paid. At odds of 11 the free bet keeps about 85% of its value; at odds of 2 it would keep under 50%.
What is liability?
The amount you lose at the exchange if the outcome you laid happens: lay stake × (lay odds − 1). You must have it in your exchange account.
What commission should I enter?
The exchange's commission on net winnings – commonly 2% to 5%. Most bookmakers charge no commission, so leave that field at 0.