| Leg | Running stake | Lay stake | Liability | P&L if fails |
|---|---|---|---|---|
| Enter stake and odds to calculate | ||||
Enter your accumulator details to see the optimal lay stake for each leg. The sequential lay method locks in a controlled loss regardless of which leg fails — protecting you at every stage of the acca.
| Selection | Stake | Odds | Return | Impl. prob |
|---|---|---|---|---|
| Enter stake and odds to calculate | ||||
Dutching splits your total stake so every selection returns the same amount. If the book % is under 100%, there's a guaranteed profit — this is an arbitrage. Over 100% means you'll always lose. Find the best available odds across multiple bookmakers to get the book % as low as possible.
| Outcome | Bookie | Exchange | Net P&L |
|---|---|---|---|
| Enter values to calculate | |||
An each way bet is two bets: one on the horse to win, one on it to place. You lay both parts separately — the win part in the Win market, the place part in the Place market. The three outcomes (wins / places only / loses) will all give a near-identical small qualifying loss when properly matched.
| Decimal | Fractional | American | Probability |
|---|
Decimal: Total return per $1 staked (includes stake). Common in Europe and Australia.
Fractional: Profit relative to stake. 5/1 means $5 profit per $1 staked.
American: Positive = profit on $100 stake. Negative = stake needed to win $100.
Probability: The implied win chance baked into the odds. Lower odds = higher implied probability.
| Leg | Selection | Odds | Running odds | Return if wins here |
|---|---|---|---|---|
| Enter stake and odds to calculate | ||||
An accumulator multiplies the odds of each selection together. Every winning leg rolls your stake and winnings into the next selection. All legs must win — a single loss loses the entire bet. Mark a leg as Void/NR to remove it from the calculation (stake rolls over as-is).
Bookmakers spend heavily to attract new customers, usually with offers like "bet $10, get a $20 free bet". They take a short-term loss to get you through the door, expecting to win it back over time. Matched betting flips that around: instead of gambling with the bonus and hoping, you use simple maths to extract its value as guaranteed profit — no matter the result of any match.
Matched betting is the technique of covering every possible outcome of an event so the bets cancel each other out. You qualify for a free bet for next to nothing, then repeat the process with the free bet to lock in a fixed profit.
It is not about predictions, tips, or luck. Every position is calculated before you place it (the calculators on this site do the maths for you), so you know your profit and loss for every outcome in advance.
Imagine a bookmaker offers a $20 free bet when you place a $10 bet on any event. To keep it simple, suppose the event is a coin toss at even odds — heads or tails.
If you bet $10 on heads and $10 on tails, one bet wins $10 and the other loses $10. They cancel out — but you've met the offer's only condition: placing a $10 bet.
| Result | $10 on Heads | $10 on Tails | Outcome |
|---|---|---|---|
| Heads wins | + $10 | − $10 | $0 — free bet unlocked |
| Tails wins | − $10 | + $10 | $0 — free bet unlocked |
Now you hold a free bet. You could gamble it — but matched betting means repeating the same trick. Place the free bet on heads, and a smaller cash bet on tails sized so that both outcomes pay the same profit:
| Result | $10 free bet on Heads | $5 on Tails | Profit |
|---|---|---|---|
| Heads wins | + $10 | − $5 | $5 |
| Tails wins | $0 (free bet, nothing lost) | + $5 | $5 |
Either way you walk away with $5. In this toy example you extract 50% of the free bet's value; on real markets you'll typically extract around 75–80% — so a $50 free bet is worth roughly $40 in cash profit.
Real events rarely have two equal outcomes. A football match can end in a home win, away win, or draw — covering all three with separate bookmaker bets would be clumsy. Instead, matched bettors use a betting exchange.
An exchange is like a bookmaker, with one key difference: you bet against other people, not the house. That means you can take either side of a bet:
Laying is what makes matched betting practical. If you back Liverpool to win at the bookmaker and lay Liverpool at the exchange, the lay bet covers both the draw and the away win — every outcome is covered with just two bets.
When you lay a bet, you stand to pay out the backer's winnings if they're right. That amount is your liability, and you need enough funds in your exchange account to cover it. For example, laying $10 at odds of 3.0 means a liability of $20 — that's what you'd pay out if the outcome happens. Don't let liability scare you: when it's lost at the exchange, your bookmaker bet has won and covers it.
Exchanges earn by charging a small commission (typically 0–5%) on net winnings. The calculators on this site include a commission field, so it's always factored into your lay stake automatically.
Here's the full process for a typical welcome offer — "bet $10, get $50 in free bets" — using realistic numbers.
You'll need one exchange account alongside your bookmaker accounts. Look for low commission and good liquidity (enough money in the market to match your bets at fair odds).
Decimal odds make comparison instant: returns = stake × odds. A $10 bet at 2.50 returns $25 ($15 profit plus your $10 stake back). Exchanges use decimal odds by default; most bookmakers let you switch in the account settings or at the top of the page.
The bet that unlocks your free bet is called the qualifying bet. Read the offer terms first — typical conditions are a minimum stake, minimum odds (often 2.00+), and a settlement deadline.
Pick a popular market — a big football match is ideal, since high liquidity means tighter back/lay odds. For qualifying bets, keep the odds low (close to the minimum the offer allows) and look for back and lay odds that are as close together as possible. That keeps your qualifying loss to pennies.
Say you back Liverpool at 2.50 with $10 at the bookmaker, and the exchange lays Liverpool at 2.60. Open the in Qualifying Bet mode, enter your back stake and both sets of odds, and it tells you the exact lay stake — here about $9.62, with a liability of about $15.39.
| Outcome | Bookmaker | Exchange | Net |
|---|---|---|---|
| Liverpool win | + $15.00 | − $15.39 | − $0.39 |
| Draw or away win | − $10.00 | + $9.62 | − $0.38 |
Whatever happens, you lose at most $0.39 — and you've unlocked $50 in free bets.
Same process, two changes. First, most free bets are stake not returned (SNR) — you keep only the winnings, not the free bet stake — so tick the matching setting in the calculator's Free Bet mode. Second, place free bets at high odds (5.0+ is ideal): the higher the odds, the larger the share of the free bet you convert to cash.
Example: a $10 free bet on Chelsea at back odds of 5.00, lay odds 5.30. The calculator gives a lay stake of about $7.55 (liability ≈ $32.46):
| Outcome | Bookmaker | Exchange | Net |
|---|---|---|---|
| Chelsea win | + $40.00 | − $32.46 | + $7.54 |
| Chelsea lose or draw | $0 (free bet) | + $7.55 | + $7.55 |
That's a guaranteed ~$7.55 from a $10 free bet — about 75% extraction. Repeat for the rest of your free bets, and a $50 package nets roughly $37 profit after the qualifying loss.
Matched betting works because you cover every outcome: a qualifying bet unlocks the bonus at near-zero cost, and laying the free bet converts most of its face value into withdrawable cash. The process is identical for every offer — only the numbers change, and the calculators handle those.
When you're ready, work through the welcome offers on the calculator pages one at a time. Each "Load offer" button pre-fills the calculator with that offer's parameters, so you can see your expected profit before you stake anything.