American (+150 / -200)

Tied to a 100-unit reference. Positives show profit on a 100 stake; negatives show the stake required to win 100. Default at US sportsbooks.

Total return per unit staked, including stake. Multiply leg decimals together to get the parlay's combined decimal.

Net profit numerator over stake denominator. 3/2 means risk 2 to win 3 plus your stake. Default at UK windows and on horse racing boards.

Net profit per unit staked, stake excluded. Equivalent to decimal odds minus one.

Indonesian (1.50 / -2.00)

American odds scaled down by a factor of 100. Common across Indonesian and Singaporean books.

Bounded between -1 and +1. Positives are underdogs, negatives are favourites. Common at Malaysian sportsbooks.

Implied probability (40%)

The break-even hit rate at the offered price. Multiply each leg's implied figure together to get the parlay's combined implied probability.

Parlay Calculator: How Much Does Each Extra Leg Actually Cost?

Parlay Calculator

Combine multiple bets into one wager. All legs must win for the parlay to pay.

Stake Odds format

Parlay legs

Combined odds (decimal) -

Combined odds (American) -

Total payout -

Net profit -

Implied probability -

How a parlay actually works

A parlay (or accumulator, multi, combo, depending on which corner of the world your sportsbook is from) packages two or more independent selections into a single wager. Every leg has to land. One miss and the whole ticket loses. In return, the price scales multiplicatively rather than additively, which is why a 4-leg ticket at standard -110 prices pays around twelve to one rather than the roughly even money you'd get from each leg on its own.

This tool takes the decimal odds of every leg you enter, multiplies them, applies your stake, and surfaces three numbers you actually care about: total payout, net profit on a win, and the implied probability of the full ticket hitting. Useful for sizing a stake against a target payout, sanity-checking what a book is offering on a built ticket, or seeing exactly how much each extra leg shrinks your chance of a winning slip.

What 100 staked across n legs looks like

All legs priced at the standard -110 (decimal 1.9091). Add one leg, multiply the decimal by 1.9091, and watch the implied probability collapse:

Legs	Combined decimal	Combined American	Total payout	Net profit	Implied %
2	3.6446	+264	364.46	264.46	27.44
3	6.9579	+596	695.79	595.79	14.37
4	13.2833	+1228	1,328.33	1,228.33	7.53
5	25.3591	+2436	2,535.91	2,435.91	3.94
6	48.4127	+4741	4,841.27	4,741.27	2.07
10	643.08	+64208	64,308.16	64,208.16	0.16

The hidden cost

Every -110 single carries roughly 4.5% in margin for the book. Parlay those legs together and the margins compound: a 4-leg parlay at four -110s prices at an effective hold near 18%, not 4.5%. The payout column is real, the math is real, but expected value is materially worse than placing the same selections as separate singles. Parlays make rational sense when you genuinely have an edge on every leg, or when the entertainment value of a long-shot ticket is worth the negative EV you are accepting.

One important caveat: this calculator assumes legs are statistically independent of each other. Correlated parlays (a team to win plus the same team to cover, for example) are a different mathematical animal. Most books either restrict them outright or re-price the combination via a same-game parlay engine that bakes in the correlation. The number you see here is the standard independent-legs calculation.

Quick reference: what each odds format means

American (+150 / -200): Tied to a 100-unit reference. Positives show profit on a 100 stake; negatives show the stake required to win 100. Default at US sportsbooks.
Decimal (2.50): Total return per unit staked, including stake. Multiply leg decimals together to get the parlay's combined decimal.
Fractional (3/2): Net profit numerator over stake denominator. 3/2 means risk 2 to win 3 plus your stake. Default at UK windows and on horse racing boards.
Hong Kong (1.50): Net profit per unit staked, stake excluded. Equivalent to decimal odds minus one.
Indonesian (1.50 / -2.00): American odds scaled down by a factor of 100. Common across Indonesian and Singaporean books.
Malay (0.50 / -0.67): Bounded between -1 and +1. Positives are underdogs, negatives are favourites. Common at Malaysian sportsbooks.
Implied probability (40%): The break-even hit rate at the offered price. Multiply each leg's implied figure together to get the parlay's combined implied probability.