Odds converter: American, decimal, fractional and implied probability
Short answer: +150 American = 2.50 decimal = 3/2 fractional = 40.0% implied probability; -150 = 1.67 = 2/3 = 60.0%. Positive American odds are the profit on a $100 stake; negative odds are the stake needed to win $100.
Fill in one box. American is used first if more than one is filled.
| American | +150 |
| Decimal | 2.500 |
| Fractional | 3/2 |
| Implied probability | 40.00% |
| Profit on a $100 stake | $150.00 |
| Stake to win $100 | $66.67 |
Showing a worked example. Enter your own numbers above; the result's link can be shared.
The conversions
- American → decimal: positive odds: 1 + odds ÷ 100 (+150 → 2.50). Negative odds: 1 + 100 ÷ |odds| (-150 → 1.667).
- American → implied probability: positive: 100 ÷ (odds + 100) (+150 → 40%). Negative: |odds| ÷ (|odds| + 100) (-150 → 60%).
- Decimal → American: 2.00 or more: (decimal − 1) × 100. Below 2.00: −100 ÷ (decimal − 1).
- Probability → American: above 50%: −100 × p ÷ (1 − p). Below 50%: 100 × (1 − p) ÷ p.
Reading American odds
A plus sign shows how much a $100 bet profits (+150 pays $150 profit). A minus sign shows how much you must stake to profit $100 (-150 means risk $150 to win $100). +100 and -100 are both even money.
Implied probability includes the bookmaker's margin. To see the fair probability of a two-way market, remove the vig with the no-vig calculator.
Other tools: No-vig calculator: remove the vig from any two-way odds · Expected value (EV) calculator for sports bets. Guides: Learn.
Arithmetic only, not betting advice. 21+. Problem gambling? Call 1-800-GAMBLER.