Betting Odds Converter
Convert American, decimal, and fractional odds to a win percentage in one place.
Enter odds in any format and the converter shows the other two formats plus the win percentage. Use it to read a price quoted in a format you do not think in, or to compare prices across books that quote differently.
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How the Odds Converter works
What is a betting odds converter?
A betting odds converter translates a price between the three common formats, American (-110, +150), decimal (1.91, 2.50), and fractional (10/11, 3/2), and shows the win percentage the price represents. It saves you the mental math when a book quotes one format and you think in another.
How to convert odds to a percentage
For positive American odds the percentage is 100 / (odds + 100), so +150 is 40%. For negative odds it is |odds| / (|odds| + 100), so -150 is 60%. For decimal odds it is 1 / decimal, so 2.50 is 40%. The converter does all of this as you type. To go further, into break-even rates, true probability with the vig removed, and whether a price is value, use the implied probability calculator.
Decimal to American odds
At 2.00 or higher, American odds = (decimal - 1) x 100, so 3.50 is +250. Below 2.00, American odds = -100 / (decimal - 1), so 1.80 is -125. Fractional is decimal minus one written as a fraction: 3.50 is 5/2 and 1.80 is 4/5.
Percentage to American odds
Type a percentage with a % sign, like 60%, and the converter returns the matching American, decimal, and fractional odds. The math: at 50% or higher, American odds = -(percentage / (100 - percentage)) x 100, so 60% is -150. Below 50%, American odds = ((100 - percentage) / percentage) x 100, so 40% is +150. 50% is even money, +100.
American to decimal, the quick math
For positive American odds, decimal = (odds / 100) + 1, so +150 becomes 2.50. For negative odds, decimal = (100 / |odds|) + 1, so -110 becomes 1.91. Decimal is the easiest format for comparing prices, because a bigger number always means a bigger payout.
Why the percentage matters
The percentage is the break-even win rate a bet needs to be profitable. If a price works out to 55% but you think the real chance is higher, it is a value bet. This is the first step toward betting with an edge instead of guessing.
Odds Converter examples
-110 in every format
-110 is 1.91 in decimal (100 / 110 + 1), 10/11 in fractional, and 52.4% as a percentage. It is the standard price on a point spread or total.
+250 in every format
+250 is 3.50 in decimal (250 / 100 + 1), 5/2 in fractional, and 28.6% as a percentage (100 / 350).
Decimal 1.80 to American
1.80 is below 2.00, so it is a favorite: -100 / 0.80 = -125. In fractional it is 4/5, and as a percentage it is 1 / 1.80 = 55.6%.
65% to odds
65% is above 50%, so the American price is negative: -(65 / 35) x 100 = -186. In decimal that is 1 / 0.65 = 1.54. Type 65% into the converter to get the same result.
Odds conversion chart
Every common American price converted to decimal odds, fractional odds, and a win percentage (odds to percentage). Favorites (minus) sit at the top, underdogs (plus) below. Type any price into the converter above for a value not listed here.
| American | Decimal | Fractional | Win % |
|---|---|---|---|
| -2000 | 1.05 | 1/20 | 95.2% |
| -1000 | 1.10 | 1/10 | 90.9% |
| -500 | 1.20 | 1/5 | 83.3% |
| -400 | 1.25 | 1/4 | 80.0% |
| -300 | 1.33 | 33/100 | 75.0% |
| -250 | 1.40 | 2/5 | 71.4% |
| -200 | 1.50 | 1/2 | 66.7% |
| -175 | 1.57 | 57/100 | 63.6% |
| -150 | 1.67 | 67/100 | 60.0% |
| -140 | 1.71 | 71/100 | 58.3% |
| -130 | 1.77 | 77/100 | 56.5% |
| -125 | 1.80 | 4/5 | 55.6% |
| -120 | 1.83 | 83/100 | 54.5% |
| -115 | 1.87 | 87/100 | 53.5% |
| -110 | 1.91 | 91/100 | 52.4% |
| -105 | 1.95 | 19/20 | 51.2% |
| +100 | 2.00 | 1/1 | 50.0% |
| +105 | 2.05 | 21/20 | 48.8% |
| +110 | 2.10 | 11/10 | 47.6% |
| +115 | 2.15 | 23/20 | 46.5% |
| +120 | 2.20 | 6/5 | 45.5% |
| +125 | 2.25 | 5/4 | 44.4% |
| +130 | 2.30 | 13/10 | 43.5% |
| +140 | 2.40 | 7/5 | 41.7% |
| +150 | 2.50 | 3/2 | 40.0% |
| +175 | 2.75 | 7/4 | 36.4% |
| +200 | 3.00 | 2/1 | 33.3% |
| +250 | 3.50 | 5/2 | 28.6% |
| +300 | 4.00 | 3/1 | 25.0% |
| +400 | 5.00 | 4/1 | 20.0% |
| +500 | 6.00 | 5/1 | 16.7% |
| +750 | 8.50 | 15/2 | 11.8% |
| +1000 | 11.00 | 10/1 | 9.1% |
| +2000 | 21.00 | 20/1 | 4.8% |
The percentage is the break-even win rate a price is asking you to believe. Anything you can beat is a value bet. For break-even rates and the true probability with the book's margin taken out, use the implied probability tool, or devig both sides of a market with the no-vig calculator.
Frequently asked questions
How do I convert odds to a percentage?+
Divide 100 by the odds plus 100 for positive American odds, divide the odds by the odds plus 100 for negative American odds (ignoring the minus sign), or divide 1 by the decimal odds. The converter does it for you.
What are -110 odds as a percentage?+
-110 American odds work out to about 52.4%, which is the break-even rate on a standard point spread.
What is +150 in decimal odds?+
+150 American odds equal 2.50 in decimal odds and 3/2 in fractional, which works out to a 40% win chance.
How do I convert decimal odds to American odds?+
Use (decimal - 1) x 100 when the decimal is 2.00 or higher, and -100 / (decimal - 1) when it is below 2.00. So 3.50 is +250 and 1.80 is -125.
Why do the percentages add up to more than 100%?+
Because the price includes a margin. When you convert both sides of a market and they total more than 100%, the excess is the built-in fee. Divide each side by that total to remove the margin and reveal the true probability, which sums to exactly 100%.
Is this odds converter free?+
Yes. It is free and needs no signup. When you want to actually bet those numbers at a better price, you can do that on BettorEdge.