Odds converter and implied probability
Type odds in any format, a percentage, or a prediction market price in cents, and get the other formats and what a stake returns.
19+ in most of Canada (18+ in Alberta, Manitoba and Quebec), 21+ in most US states. A calculator shows what a bet pays, not how likely it is to win. Free help: 1-800-GAMBLER (US), ConnexOntario 1-866-531-2600 (Ontario), 211 (Alberta). More help.
Conversion formulas
- American to decimal:
1 + A/100if A is positive,1 + 100/|A|if negative. - Decimal to American:
(D − 1) × 100if D ≥ 2,−100 / (D − 1)if D < 2. - Fractional to decimal:
N/D + 1. - Odds to percentage (implied probability):
100 / decimal odds; percentage to decimal odds:100 / percentage. - Prediction market price (¢ per $1 contract) to decimal odds:
100 / price, before fees.
Common odds
| Fractional | Decimal | American | Implied probability |
|---|---|---|---|
| 1/5 | 1.20 | −500 | 83.3% |
| 1/3 | 1.33 | −300 | 75.0% |
| 1/2 | 1.50 | −200 | 66.7% |
| 4/6 | 1.67 | −150 | 60.0% |
| 10/11 | 1.91 | −110 | 52.4% |
| evs | 2.00 | +100 | 50.0% |
| 6/5 | 2.20 | +120 | 45.5% |
| 6/4 | 2.50 | +150 | 40.0% |
| 2/1 | 3.00 | +200 | 33.3% |
| 5/2 | 3.50 | +250 | 28.6% |
| 3/1 | 4.00 | +300 | 25.0% |
| 4/1 | 5.00 | +400 | 20.0% |
| 5/1 | 6.00 | +500 | 16.7% |
| 10/1 | 11.00 | +1000 | 9.1% |
| 20/1 | 21.00 | +2000 | 4.8% |
-110, the standard US spread price, is 1.909 in decimal, 10/11 as a fraction and 52.4% implied.
Questions
How do I convert American odds to decimal?
Plus odds: 1 + odds ÷ 100, so +150 is 2.50. Minus odds: 1 + 100 ÷ |odds|, so -110 is 1.909.
How do I convert fractional odds to decimal?
Divide and add 1: 6/4 is 1.5 + 1 = 2.50. Evens (1/1) is 2.00.
What is implied probability?
The chance of winning that the odds suggest: 1 ÷ decimal odds. 2.50 (+150, 6/4) implies 40%. Bookmaker odds include a margin, so the implied chances of all outcomes add up to more than 100%.
How do I convert odds to a percentage?
Divide 100 by the decimal odds: 2.50 is 100 ÷ 2.5 = 40%. Going the other way, percentage to odds: decimal odds = 100 ÷ percentage, so 25% is 4.00 (+300, 3/1).
How do prediction market prices compare with sportsbook odds?
A contract that pays $1 if the event happens and costs 62¢ implies a 62% chance, the same as decimal odds of 1.61 or -163, before the exchange's fees. Enter the price in cents to convert it.
What do minus and plus mean in American odds?
Minus odds show how much you stake to win $100 (-150: stake $150 to win $100). Plus odds show how much a $100 stake wins (+150: win $150).