Before you lock in a multi, it pays to know three things: what the combined odds are, what you will get back if it lands, and how likely it really is to win. Our free multi bet calculator shows all three for any number of legs, and it handles scratchings and dead heats the way Australian bookmakers settle them.
Enter the decimal odds for each leg and your stake. Mark legs as won, lost or scratched as results come in. Calculations update instantly and nothing is saved.
A multi (also called an accumulator or parlay) combines two or more selections into one bet. Every leg must win. In return, the odds of each leg are multiplied together, so the payout grows quickly.
Formula: Combined odds = Leg 1 odds × Leg 2 odds × Leg 3 odds …
Total return = Stake × Combined odds
Profit = Total return − Stake
| Leg | Selection | Decimal odds | Running combined odds |
|---|---|---|---|
| 1 | Team A to win | $1.80 | 1.80 |
| 2 | Team B to win | $2.10 | 3.78 |
| 3 | Horse C to win | $1.65 | 6.24 |
With a $10 stake, this multi returns $62.37 (profit of $52.37) if all three legs win. If you had placed three separate $10 singles instead, all three winning would return $55.50 from a $30 outlay – a smaller profit, but you would still collect on the legs that won if one lost.
Adding legs makes the payout look exciting, but the chance of landing the whole multi falls just as fast. The table below assumes every leg is priced at $1.90 – a typical price for a close head-to-head or line bet – and a $10 stake.
| Legs | Combined odds | Return on $10 | Chance implied by the odds | Roughly |
|---|---|---|---|---|
| 2 | 3.61 | $36.10 | 27.7% | About 1 in 4 |
| 3 | 6.86 | $68.59 | 14.6% | About 1 in 7 |
| 4 | 13.03 | $130.32 | 7.7% | About 1 in 13 |
| 5 | 24.76 | $247.61 | 4.0% | About 1 in 25 |
| 6 | 47.05 | $470.46 | 2.1% | About 1 in 47 |
| 7 | 89.39 | $893.87 | 1.1% | About 1 in 89 |
| 8 | 169.84 | $1,698.36 | 0.59% | About 1 in 170 |
This is the main reason most experienced punters keep multis to two to four legs. Our guide to building a winning multi-bet strategy explains how to choose legs that work well together.
Bookmakers build a margin into every price. On a true 50/50 contest, the fair price is $2.00 for each side, but bookmakers usually offer around $1.90. That works out to an overround of about 5.3% on that market.
In a multi, that margin compounds with every leg. The table shows the long-run return you can expect for every $100 staked when each leg is a 50/50 contest priced at $1.90:
| Legs | Expected long-run return | Expected long-run cost |
|---|---|---|
| 1 | 95.0% | 5.0% |
| 2 | 90.3% | 9.8% |
| 3 | 85.7% | 14.3% |
| 4 | 81.5% | 18.5% |
| 5 | 77.4% | 22.6% |
| 6 | 73.5% | 26.5% |
What this means for you: multis are fun, but the more legs you add, the more of your stake goes to the bookmaker over time. Shopping around for the best odds on each leg is one of the few ways to claw some of that back – even moving from $1.90 to $1.95 on every leg makes a noticeable difference over a season.
Things do not always go to plan. Here is how Australian bookmakers generally settle a multi when a leg is affected. Always check your bookmaker’s own rules, as details vary.
| What happens | How the leg is treated | Effect on your multi |
|---|---|---|
| Horse is scratched | The leg is made void (odds of 1.00) | Your multi stands on the remaining legs, at lower odds |
| Match is abandoned or postponed | Usually void if not completed within the bookmaker’s time limit | Settled on the remaining legs |
| Two-way dead heat for 1st | Odds for that leg are halved (half your stake wins at full odds) | The multi still wins, but the payout is lower |
| Three-way dead heat | Odds are divided by three | Payout drops further |
| Draw in a head-to-head market | Treated as a loss if the draw was a possible result | The multi loses |
| Draw in a draw-no-bet market | The leg is voided | Settled on the remaining legs |
The calculator above lets you mark a leg as “Scratched / void” or “Dead heat (2-way)” so you can see exactly how your return changes.
A combo multi (sometimes called a boxed multi) places several smaller multis from your selections at once. For example, picking four teams as “3-leg combos” places every possible 3-leg multi from those four teams. If one team loses, one of the combos can still win.
The trade-off is cost: you pay a stake for every combination. Here is how many bets each combo creates and what it costs at $1 per combination:
| Your picks | Combo type | Number of multis | Cost at $1 each |
|---|---|---|---|
| 3 selections | 2-leg multis | 3 | $3.00 |
| 4 selections | 2-leg multis | 6 | $6.00 |
| 4 selections | 3-leg multis | 4 | $4.00 |
| 5 selections | 2-leg multis | 10 | $10.00 |
| 5 selections | 3-leg multis | 10 | $10.00 |
| 5 selections | 4-leg multis | 5 | $5.00 |
| 6 selections | 3-leg multis | 20 | $20.00 |
| 6 selections | 4-leg multis | 15 | $15.00 |
For a deeper look, read our guide to multi-bet combinations and how combo multis work.
A same game multi (SGM) combines several outcomes from one match, such as a team to win plus a player to score. Because those outcomes are linked – if a team wins big, its best player is more likely to score – bookmakers price SGMs lower than simply multiplying the individual odds.
That means the multi calculator will show a higher price than the SGM your bookmaker offers. That is normal, not an error. Use the calculator for multis across different games, and treat the bookmaker’s SGM price as the real price for same-game bets.
Australian bookmakers show decimal odds, which already include your stake. Some international sites use fractional odds. The “implied chance” is what the price says about the likelihood of a result, before allowing for the bookmaker margin.
| Decimal odds | Fractional odds | Implied chance |
|---|---|---|
| $1.25 | 1/4 | 80.0% |
| $1.50 | 1/2 | 66.7% |
| $1.80 | 4/5 | 55.6% |
| $2.00 | 1/1 | 50.0% |
| $2.50 | 3/2 | 40.0% |
| $3.00 | 2/1 | 33.3% |
| $4.00 | 3/1 | 25.0% |
| $5.00 | 4/1 | 20.0% |
| $10.00 | 9/1 | 10.0% |
Need more help reading prices? See our guide on how to read betting odds for NRL and AFL matches.
As the tables above show, every extra leg cuts your chance sharply. A short multi of strong selections lands far more often than a long one built for a huge payout.
A simple test: if you would not bet on a leg on its own, do not add it just to inflate the odds.
Small differences multiply. Check a couple of bookmakers before placing a multi, and use our odds comparison calculator to see what the better price is worth – our sportsbook reviews compare the main Australian options.
Decide what you can afford to lose before the round starts. Since June 2024, Australian bookmakers can no longer accept credit cards or cryptocurrency for online betting, so you can only bet with money you already have. Deposit limits and the national self-exclusion register, BetStop, are free tools that help you stay in control.
Multiply the decimal odds of every leg together to get the combined odds, then multiply by your stake. For example, legs at $1.80, $2.10 and $1.65 give combined odds of 6.24, so a $10 stake returns $62.37.
The scratched leg is usually voided (treated as odds of 1.00), and your multi is settled on the remaining legs at lower combined odds. Check your bookmaker’s rules for the exact details.
Yes. “Total return” includes your stake, which is how decimal odds work. “Profit” is the return minus your stake.
Same game multi legs are related, so bookmakers reduce the price to account for that link. The calculator multiplies odds as if the legs were independent, which is correct for multis across different games.
Most experienced punters stick to two to four legs. With every leg at $1.90, a 4-leg multi lands roughly 1 time in 13 according to the odds, while an 8-leg multi lands roughly 1 time in 170.
A combo multi places every possible smaller multi from your selections, such as all 3-leg multis from four picks. It costs more, because you pay for each combination, but one losing leg does not end the whole bet.
It is the probability suggested by the odds, calculated as 1 divided by the decimal odds for each leg, multiplied together. Because bookmakers build in a margin, the true chance is usually a little lower.
The calculator uses decimal odds, which is what Australian bookmakers display. Use the conversion table on this page to convert fractional odds first.
A multi is one of the most exciting bets you can place, and knowing the real numbers makes it a smarter one. Use the calculator to check your return and your actual chance before you bet, keep your legs to a sensible number, and always set a budget first.
For more help, read our multi-bet strategy guide, our betting guide and our responsible gaming page.
👉 Compare trusted bookmakers in our sportsbook reviews.
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