What are American odds?
American odds express every price as a number relative to $100. A positive number — +150 — is the profit on a $100 stake: bet $100, win $150, collect $250 total. A negative number — −110 — is the stake required to win $100: bet $110, win $100, collect $210 total. Positive odds pay more than even money; negative odds pay less.
The sign also tells you which side the market favors. Negative prices are favorites — you risk more than you win because the outcome is likely. Positive prices are underdogs. A price of +100, called even money, sits exactly at 50/50.
Converting to decimal and implied probability
To decimal odds: for plus prices, divide by 100 and add 1 — +150 becomes 2.50. For minus prices, divide 100 by the price and add 1 — −110 becomes 1.909. Decimal is the total-return multiplier: stake times decimal equals everything you get back.
To implied probability — the breakeven win rate — for minus prices divide the price by the price plus 100: −110 is 110 ÷ 210 = 52.4%. For plus prices divide 100 by the price plus 100: +150 is 100 ÷ 250 = 40.0%. This conversion is the one that matters for every EV decision you will ever make.
Reading them like a bettor
American odds are signed, always — +120 never renders as 120, and the minus is a real minus sign. On this site, odds outside of prose always appear as pills, so you can scan a board the way you would at the book. And because every book prices the same prop independently, the difference between −110 and −105 on the same side is real money: always shop the board before you bet. Half a point of implied probability sounds small; multiplied across a full season of bets, it is often the entire difference between a winning and a losing record.
Worked example — one plus price, one minus price
- +150 to decimal
- 150 ÷ 100 + 1 = 2.500
- +150 implied probability
- 100 ÷ (150 + 100) = 40.0%
- +150 in dollars
- $100.00 staked → $250.00 back ($150.00 profit)
- −110 to decimal
- 100 ÷ 110 + 1 = 1.909
- −110 implied probability
- 110 ÷ (110 + 100) = 52.4%
- −110 in dollars
- $110.00 staked → $210.00 back ($100.00 profit)
One number, three readings: what it pays, what it implies, and what you must risk. Learn all three and any US board reads itself.
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Related terms
Frequently asked questions
What does −110 mean in dollars?▾
You risk $110 to win $100 in profit, and $210 total comes back when you win. Scaled down, that is $11 to win $10 or $1.10 to win $1 — the ratio stays the same at any stake. −110 is the default price on most two-way markets at US books.
What does +150 mean in dollars?▾
You win $150 in profit for every $100 risked, and $250 total comes back when you win. A $20 stake at +150 wins $30. Plus prices always pay more than even money because the outcome is the less likely side.
Why do sportsbooks use American odds?▾
Because US bettors grew up on them. The format centers on $100 units, which made tickets easy to write by hand. Decimal odds — dominant in Europe and on exchanges — are better for parlay math and probability work, which is why serious bettors convert between the two fluently.
Is +100 the same as even money?▾
Yes. +100 pays exactly 1-to-1: risk $100, win $100. It corresponds to a 50% implied probability and 2.00 in decimal odds. You will often see it written as EV or PK (pick’em) on a book’s board instead of +100.
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