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Betting Odds Calculator
Convert American, decimal, and fractional odds, see the implied probability, and calculate your payout and profit for any stake.
Short answer
Odds come in three formats — American (+150 / −200), decimal (2.50), and fractional (5/2) — that all describe the same bet. Convert to decimal and your payout is stake × decimal odds; your profit is that minus the stake. Implied probability is 1 ÷ decimal odds. Enter your odds in any format and a stake below to see every conversion and your payout.
Total payout
$250.00
Stake + profit
Profit
$150.00
If it wins
Implied probability
40.0%
1 ÷ decimal odds
Stake
$100
Your wager
The same odds in every format
- Decimal
- 2.50
- American
- +150
- Fractional
- 3/2
Odds & betting calculators
Odds conversion & $100 payout across formats
| Decimal | American | Fractional | Implied probability | $100 payout |
|---|---|---|---|---|
| 1.50 | -200 | 1/2 | 66.7% | $150 |
| 1.91 | -110 | 91/100 | 52.4% | $191 |
| 2.00 | +100 | 1/1 | 50.0% | $200 |
| 2.50 | +150 | 3/2 | 40.0% | $250 |
| 3.00 | +200 | 2/1 | 33.3% | $300 |
| 5.00 | +400 | 4/1 | 20.0% | $500 |
The same bet written four ways, with the total return on a $100 stake. Implied probability is 1 ÷ decimal odds; a sportsbook's margin means a market's implied probabilities add to over 100%. Informational only — this tool does not place bets.
How betting odds are calculated
Everything starts by converting to decimal odds: American +150 becomes 2.50, −200 becomes 1.50, and fractional 5/2 becomes 3.50. From decimal, your payout is stake × decimal odds and your profit is that minus the stake. Implied probability is 1 ÷ decimal odds — the win chance the price reflects. For a parlay, multiply the decimal odds of every leg, since all of them must win.
How we calculate this
Every number on this page comes from converting the odds to decimal, then applying the payout math:
- Convert to decimal. American +150 → 1 + 150/100 = 2.50; −200 → 1 + 100/200 = 1.50. Fractional 5/2 → 5/2 + 1 = 3.50. Decimal is the common denominator for every other calculation.
- Implied probability. 1 ÷ decimal odds — so 2.00 is 50%, 4.00 is 25%. It's the win chance the price implies.
- Payout & profit. total return = stake × decimal odds; profit = total return − stake. Decimal odds already include your stake back.
- Parlay. multiply the decimal odds of every leg to get the combined odds, then apply the same payout math. Every leg must win.
Assumptions
- Odds are taken as given; this tool doesn't set prices or account for line movement.
- Implied probability is the raw price with the sportsbook's margin (vig) still in it, so a market sums to over 100%.
- Fractional odds are shown as a clean approximation (denominator ≤ 100) of the decimal price.
- Informational only — not betting advice, and not a way to place bets. Gamble responsibly.
Last reviewed: July 19, 2026
Frequently asked questions
How do betting odds work?+
Odds tell you two things: how likely an outcome is and how much you'd win. American odds show +150 (win $150 on a $100 bet) or −200 (bet $200 to win $100). Decimal odds like 2.50 mean your total return is stake × 2.50. Fractional odds like 5/2 mean you win $5 for every $2 staked. This calculator converts between all three and shows the payout for any stake.
How do I calculate a betting payout?+
Convert the odds to decimal, then multiply by your stake for the total return; subtract the stake for your profit. So $100 at decimal 2.50 returns $250 (a $150 profit); $100 at American −200 (decimal 1.50) returns $150 (a $50 profit). Enter your odds and stake above and the calculator shows both the total payout and the profit.
What is implied probability?+
Implied probability is the win chance the odds represent, found by dividing 1 by the decimal odds. Decimal 2.00 implies 50%, 4.00 implies 25%, and 1.50 implies about 67%. It's useful for spotting value: if you think the true chance is higher than the implied probability, the odds may be worth taking. Note that a sportsbook's odds add a margin, so implied probabilities across a market sum to more than 100%.
How does a parlay calculator work?+
A parlay (or accumulator) combines several bets into one, and every leg must win. To find the combined odds, convert each leg to decimal and multiply them together, then multiply by your stake for the payout. Three legs at 2.00, 1.50, and 2.50 combine to 7.50, so a $100 parlay returns $750. The upside is big, but the odds of hitting every leg are much lower — the parlay tab handles the math.
What's the difference between American, decimal, and fractional odds?+
They're three ways to write the same thing. American (moneyline) is common in the US: positive numbers show profit on a $100 bet, negative show the stake needed to win $100. Decimal, common in Europe and Australia, is the total return per $1 staked. Fractional, traditional in the UK, shows profit-to-stake as a fraction. This tool converts any one into the other two instantly.
Is this calculator for placing bets?+
No. It's an informational tool for understanding odds, payouts, and probabilities — it doesn't place bets or connect to any sportsbook. Gambling carries real financial risk, the house always has a margin built into the odds, and you should only ever wager what you can afford to lose. If gambling stops being fun or feels out of control, help is available (in the US, call or text 1-800-GAMBLER).
Related tools
This is an informational tool for understanding odds and payouts — it does not place bets or set prices. Gambling carries real financial risk and the odds always include the house's margin; only wager what you can afford to lose. If gambling feels out of control, help is available: in the US, call or text 1-800-GAMBLER.