American Odds Calculator & Converter
Enter any American price (+150, −110) — or a decimal or fractional one — and this free American odds calculator instantly shows your payout and profit for any stake, plus all four formats and the implied probability. Pick a tab and it converts live, both directions — a betting odds converter and payout calculator in one.
Why odds conversion matters for +EV betting
Odds conversion looks like bookkeeping, but it is the first step in every profitable betting workflow. Positive EV betting means finding prices where the implied probability a sportsbook is charging is lower than the outcome's real chance — and you can't see that until you translate +150 or −110 into a percentage. Converting to decimal also makes prices comparable: 2.05 versus 2.00 looks like pocket change, but that 2.5% gap is often the entire edge on a wager. Sharp bettors convert constantly — American to implied probability to judge a price, decimal to line-shop across US books and exchanges, then back again to place the bet. Strip the vig from the implied number and you have a fair probability to bet against. If that framework is new, start with the guide to positive EV betting, then price your edge in the EV betting calculator.
How each format relates
All four formats describe the same thing — the payout on a winning bet — in different clothing. Everything is easiest to reason about through decimal odds, which is just the total return per $1 staked (stake included).
For example, +150 is decimal 2.50, fractional 3/2, and an implied probability of 40% (1 ÷ 2.50). A −110 favorite is decimal 1.909, fractional 10/11, and about a 52.4% implied chance.
How to calculate a payout from American odds
American odds are quoted relative to $100, which makes the payout math simple once you know which sign you're looking at. Positive odds tell you the profit on a $100 stake; negative odds tell you the stake needed to win $100. For any bet amount:
So $50 at +150 wins $75 profit and returns $125 total, while $110 at −110 wins $100 profit and returns $210 total. The calculator above runs this for any stake automatically — and because it also shows the implied probability, you can see in the same glance what chance of winning the book is charging you for that payout.
A note on implied probability
The implied probability a price shows always includes the bookmaker's vig, so it slightly overstates the true chance of the outcome. Add up both sides of a market and they'll exceed 100% — that overage is the margin. To recover the honest number, strip the vig out with the no-vig calculator. See the full method in the no-vig guide. Once you have the fair number, the EV betting calculator tells you whether the price you're being offered is actually worth taking. New to that idea? Start with the guide to positive EV betting.
Common odds reference
| American | Decimal | Fractional | Implied % |
|---|---|---|---|
| −200 | 1.50 | 1/2 | 66.7% |
| −150 | 1.667 | 2/3 | 60.0% |
| −110 | 1.909 | 10/11 | 52.4% |
| +100 | 2.00 | 1/1 | 50.0% |
| +150 | 2.50 | 3/2 | 40.0% |
| +200 | 3.00 | 2/1 | 33.3% |
| +300 | 4.00 | 3/1 | 25.0% |
Frequently asked questions
What is a betting odds converter?
A betting odds converter translates the same price between the notations sportsbooks use — American (+150), decimal (2.50), and fractional (3/2) — and shows the implied probability behind it. US books quote American odds, European books and exchanges use decimal, and UK books use fractional; the payout is identical, only the notation changes. This one converts in every direction at once, live as you type.
How do you convert American odds to decimal?
For positive American odds, decimal = 1 + (odds / 100). For negative American odds, decimal = 1 + (100 / |odds|). For example +150 becomes 2.50, and −110 becomes 1.909.
How do you turn odds into an implied probability?
Implied probability is simply 1 divided by the decimal odds, expressed as a percentage. Decimal 2.50 implies a 40% chance; decimal 1.909 (−110) implies about 52.4%. Note this includes the bookmaker's vig, so it slightly overstates the true probability.
How is fractional odds calculated from decimal?
Fractional odds represent the net profit per unit staked, which is the decimal odds minus 1. Decimal 2.50 minus 1 equals 1.5, or 3/2. Decimal 3.00 minus 1 equals 2, or 2/1. The converter reduces the fraction to its simplest whole-number form.
What do American odds mean?
American odds (also called moneyline odds) express a price relative to $100. Positive odds show the profit on a $100 stake: +150 pays $150 profit on $100. Negative odds show how much you must stake to win $100: −110 means risking $110 to win $100. Positive numbers mark underdogs, negative numbers mark favorites, and +100 is even money.
How do you calculate a payout from American odds?
For positive odds, profit = stake × (odds ÷ 100), so $50 at +150 wins $75 profit ($125 total back). For negative odds, profit = stake × (100 ÷ |odds|), so $110 at −110 wins $100 profit ($210 total back). Total payout is always your stake plus the profit — or stake × decimal odds. The calculator on this page does this automatically from any stake.
Odds are just the first step.
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