Odds Converter
Translate any American price into Decimal, Fractional, and implied probability.
Decimal
1.909
Fractional
91/100
Implied probability
52.38%
What this means
Implied probability is the break-even win rate the price quotes - not the true probability of the event. The gap between implied and true probability is where edge (or vig) lives. Use the EV Calculator next to compare a true estimate against the market.
The three odds formats, side by side
American, decimal, and fractional odds describe the same payout in different notation. American odds (-110, +200) are the US default. Decimal odds (1.91, 3.00) dominate Europe and Asia and are the cleanest format for math. Fractional odds (5/2, 1/4) come from the British racing tradition. Most sportsbook apps let you toggle the display in settings.
Conversion formulas
- American (negative) → Decimal: 1 + (100 / |odds|)
- American (positive) → Decimal: 1 + (odds / 100)
- Decimal ≥ 2.00 → American: (decimal − 1) × 100
- Decimal < 2.00 → American: −100 / (decimal − 1)
- Decimal → Implied probability: 1 / decimal
- Fractional N/M → Decimal: (N / M) + 1, Implied: M / (N + M)
Conversion reference table
| American | Decimal | Fractional | Implied probability |
|---|---|---|---|
| -300 | 1.333 | 1/3 | 75.0% |
| -200 | 1.500 | 1/2 | 66.7% |
| -150 | 1.667 | 2/3 | 60.0% |
| -120 | 1.833 | 5/6 | 54.5% |
| -110 | 1.909 | 10/11 | 52.4% |
| +100 | 2.000 | 1/1 | 50.0% |
| +120 | 2.200 | 6/5 | 45.5% |
| +150 | 2.500 | 3/2 | 40.0% |
| +200 | 3.000 | 2/1 | 33.3% |
| +300 | 4.000 | 3/1 | 25.0% |
| +500 | 6.000 | 5/1 | 16.7% |
Common questions
- What do +200 odds mean?
- You profit $200 on a winning $100 bet. Implied probability ≈ 33.3%.
- What do -200 odds mean?
- You must risk $200 to profit $100. Implied probability ≈ 66.7%.
- Why is -110 the standard US price?
- Books typically price both sides of spreads and totals at -110, baking in about a 4.5–4.8% theoretical hold on the market.
- Which odds format is most accurate?
- They are all equally accurate - they describe the same payout. Decimal is just the easiest to do math with.