Double Bet Calculator

This double bet calculator turns two American-odds picks into one combined price, showing the payout and profit on your stake in dollars before you risk a cent on either leg.

What Is a Double Bet?

A double is a two-pick parlay: you choose two separate selections, and both have to win for the bet to pay out. A double multiplies the two prices together rather than adding them, because you’re being paid once for the compounded difficulty of getting two picks right instead of one.

It’s the smallest bet in the accumulator family, one rung above a single. A single risks your stake on one outcome; a double asks you to be right about two at once, in exchange for a payout that grows faster than your stake did. That’s the appeal: a modest stake can turn into a meaningfully bigger return, because the two prices compound rather than stack.

The trade-off is built in. A loss on either leg sinks the whole double - there’s no partial credit for going one-for-two. That’s different from placing the same two picks as separate singles, where one win still pays even if the other loses.

US sportsbooks don’t usually list “double” as its own bet type; they fold it into the parlay menu, where a two-leg parlay is the same wager. But the math is worth isolating, because it’s the exact calculation - multiply, then multiply by stake - that every larger parlay is built from.

How a Double Bet Is Calculated

The calculation happens in three steps. First, each pick’s American odds get converted to decimal odds. The Chiefs at -150 convert to 1.67 - a negative price means you’re laying more than you stand to win, so the decimal odds stay below 2.00. The Lakers at +120 convert to 2.20 - a positive price means you stand to win more than you stake, so the decimal odds land above 2.00.

Second, the two decimal odds are multiplied together, not added. 1.67 multiplied by 2.20 gives combined odds of 3.67. This is the step that trips people up: adding -150 and +120 as raw numbers means nothing, and even adding the decimal odds would understate the payout, because a parlay’s odds compound rather than stack.

Third, the combined odds are multiplied by your stake to get the payout, and the stake is subtracted from the payout to get profit. Profit = payout - stake. On a $20 stake, combined odds of 3.67 give a payout, and that payout minus the $20 stake gives the profit.

Both legs have to win for any of this to pay out. There’s one exception: if a leg pushes - the result lands exactly on the number, with no winner or loser - it’s removed from the calculation, and the double settles as a single on whichever leg survived. A push isn’t treated as a loss; it just stops counting.

What the Calculator Shows You

Enter both picks’ American odds and your stake in dollars, and the calculator returns four figures. Combined odds show the single multiplied-together price your double is playing at, so you can see whether the payout is worth the added risk of needing two winners instead of one. Payout is what you collect in total if both legs win - stake plus profit combined. Profit is that payout with your original stake subtracted back out, the number that actually tells you what you gained. Implied probability translates the combined odds into a percentage, showing roughly how likely the book’s pricing says it is that both legs land together. Once results are in, you can mark either leg Win, Loss, or Push, and the calculator applies the push rule automatically rather than leaving you to work it out by hand.

Worked Example

Take a $20 double on two moneyline picks: the Chiefs at -150 and the Lakers at +120.

The Chiefs’ -150 converts to decimal odds of 1.67. The Lakers’ +120 converts to decimal odds of 2.20. Multiply those two together and the combined odds come out to 3.67.

Apply the $20 stake to those combined odds and the payout is $73.33. Subtract the $20 stake and the profit is $53.33. That’s the entire calculation: convert, multiply, multiply by stake, subtract stake.

Framed as implied probability, combined odds of 3.67 work out to a 27.3% chance - the book’s pricing of how likely it is that both the Chiefs and the Lakers win.

The gap between the two individual legs and the combined bet is the whole point of a double. Neither the Chiefs alone at -150 nor the Lakers alone at +120 would turn $20 into anything close to $73.33 - it’s multiplying the two prices together that produces the bigger payout.

That bigger number comes with a matching condition: both the Chiefs and the Lakers have to win. If either one loses outright, the double loses outright too - there’s no partial payout for getting one right and one wrong. The $73.33 payout and $53.33 profit only materialize if both results land as needed.

Double Payout on a $20 Stake by the Two Prices

The combined odds - and the payout they produce - depend on how big the two individual prices are. A $20 double stays modest when both legs are shorter-priced favorites, like -110 and -110, but climbs sharply once the legs get longer, as with +150 and +200. The table below holds the $20 stake constant across four price pairings, so you can see how the combined odds, payout, and profit shift as the legs move from short favorites to longer prices.

The Two Picks in Each Odds Format

The Chiefs and Lakers legs from the worked example look different depending on which odds format a sportsbook displays. American odds are the default at US books; decimal odds are what the calculator actually multiplies; fractional odds show the same price as a ratio; and implied probability translates each price into the percentage chance the book’s line represents. The table below lines up all four formats for both legs of the double.

The Vig Compounds, and a Push Settles as a Single

A double is where the vig - the sportsbook’s built-in margin - first starts to compound. Every leg carries the book’s edge on its own, and multiplying two prices together to build a double multiplies their margins together too. That’s why the combined implied probability of 27.3% on the Chiefs/Lakers double sits a touch worse than the true chance of both picks landing - the book’s edge is baked into each leg, and stacking legs stacks the edge. It’s a small gap on a two-leg double, but the same compounding is why longer parlays, with three, four, or more legs, tilt so heavily toward the house.

The push rule works in the bettor’s favor by comparison. If one leg ties on the number - a push, with no winner or loser - it doesn’t void or lose the bet. Instead, it drops out of the calculation, and the double settles as a single on the surviving leg. A push is a non-event, not a loss.

That leniency has a hard limit: it only applies to a push, not to a loss. If either leg loses outright, the whole bet loses outright with it. There’s no partial-credit version of a double where one correct pick and one incorrect pick still returns something.

When a Double Makes Sense

A double makes the most sense when you have genuine conviction on two picks and want a bigger payout than either could deliver alone, without stretching to the three, four, or five legs that push a parlay’s odds into longshot territory. Two legs is enough to compound a modest stake into a meaningfully bigger number - as the Chiefs/Lakers example shows, a $20 double turns into a $73.33 payout - while keeping the number of things that have to break your way to just two.

It’s a poor fit for anyone who wants their bankroll to move predictably. Because both legs have to win, a double is higher-variance than betting the same two picks as separate singles: singles let one winner still pay even if the other misses, while a double pays nothing unless both come through. If steady, incremental results matter more than a shot at a bigger number, two singles does that job better.

Doubles sit at the low end of the parlay ladder for a reason: they carry less compounded vig than a three-leg or five-leg parlay, so keeping it to two legs limits how much margin gets stacked against you. Reserve doubles for pairs of picks you’d happily bet individually anyway, rather than dressing up a shaky pick by attaching it to a stronger one - the shaky leg can sink the whole bet regardless of what it’s paired with.

Common Mistakes

Adding the two prices together instead of multiplying the decimal odds is the most common error, and it produces a number that doesn’t match what any sportsbook will pay. Forgetting that both picks must win trips up bettors who treat a double like two independent chances at a payout, when really one loss sinks the entire bet. It’s also easy to overlook that the vig compounds across the two legs, so the double’s true edge against the bettor is worse than either leg’s price suggests alone. Finally, treating a push as a loss works against you: a pushed leg drops out of the bet rather than costing it, and the double settles as a single on the pick that’s left.

Double vs Two Singles

A double and two singles use the same two picks but pay out on different terms. Two singles split the risk and pay independently, so one winner still returns money even if the other loses. A double combines both into one all-or-nothing wager, trading that split risk for a higher potential payout.