Odds Converter
Convert between American, decimal and fractional odds instantly — and see the implied probability of any price.
e.g. +150 or -110
American
+150
Decimal
2.50
Fractional
3/2
Implied probability
40.00%
Omenizer compares every book’s price to the fair line automatically — in whichever format you prefer.
See live value bets →Odds conversion chart
Common American, decimal and fractional odds side by side with their implied probability — from long-shot underdogs to heavy favorites.
| American | Decimal | Fractional | Implied |
|---|---|---|---|
| +2000 | 21.00 | 20/1 | 4.8% |
| +1000 | 11.00 | 10/1 | 9.1% |
| +500 | 6.00 | 5/1 | 16.7% |
| +400 | 5.00 | 4/1 | 20.0% |
| +300 | 4.00 | 3/1 | 25.0% |
| +250 | 3.50 | 5/2 | 28.6% |
| +200 | 3.00 | 2/1 | 33.3% |
| +175 | 2.75 | 7/4 | 36.4% |
| +150 | 2.50 | 3/2 | 40.0% |
| +125 | 2.25 | 5/4 | 44.4% |
| +110 | 2.10 | 11/10 | 47.6% |
| +100 | 2.00 | 1/1 | 50.0% |
| −110 | 1.91 | 10/11 | 52.4% |
| −120 | 1.83 | 5/6 | 54.5% |
| −150 | 1.67 | 2/3 | 60.0% |
| −175 | 1.57 | 4/7 | 63.6% |
| −200 | 1.50 | 1/2 | 66.7% |
| −250 | 1.40 | 2/5 | 71.4% |
| −300 | 1.33 | 1/3 | 75.0% |
| −400 | 1.25 | 1/4 | 80.0% |
| −500 | 1.20 | 1/5 | 83.3% |
| −750 | 1.13 | 2/15 | 88.2% |
| −1000 | 1.10 | 1/10 | 90.9% |
Worked examples
- • +150 to decimal: (150 ÷ 100) + 1 = 2.50. Implied probability = 1 ÷ 2.50 = 40%. Fractional = 3/2.
- • −120 to decimal: (100 ÷ 120) + 1 = 1.83. Implied = 1 ÷ 1.83 = 54.5%. Fractional = 5/6.
- • 2.20 decimal to American: decimal ≥ 2, so (2.20 − 1) × 100 = +120. Implied = 45.5%.
- • 1.50 decimal to American: decimal < 2, so −100 ÷ (1.50 − 1) = −200. Implied = 66.7%.
FAQ
- How do I convert American odds to decimal?
- For positive American odds: decimal = (american / 100) + 1. For negative: decimal = (100 / |american|) + 1. E.g. +150 → 2.50, −120 → 1.833.
- How do I convert decimal odds to American?
- If decimal ≥ 2.0: american = (decimal − 1) × 100. If decimal < 2.0: american = −100 / (decimal − 1). E.g. 2.50 → +150, 1.50 → −200.
- What is implied probability?
- The probability an outcome implied by its odds: implied % = 1 / decimal odds. It includes the bookmaker’s margin, so the total across all outcomes is over 100%.
- What are fractional odds?
- The UK format showing profit per stake — 3/2 means you win 3 for every 2 staked (decimal 2.50). Convert to decimal by dividing and adding 1: (3 ÷ 2) + 1 = 2.50.
- Which odds format is best?
- Decimal is the easiest for math — payout = stake × decimal, and implied probability = 1 ÷ decimal. American is standard at US books; fractional is common in the UK and horse racing. They all describe the same price.
- Why do the same odds look different across sportsbooks?
- They’re quoting the same price in different formats, and margins vary. Converting to a common format (or to implied probability) lets you line-shop and spot which book has the best number.
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Built by the team behind Omenizer’s real-time fair-odds engine — the same devigging and closing-line-value math that powers our live value-bet feed. Last updated July 2026.
Educational tool only. Implied probability includes the bookmaker margin.