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Odds Converter
American1.909 decimal
Hong Kong, Malay and Indonesian odds
Hong Kong is the net per unit staked. Malay and Indonesian flip to a negative number on one side of even money.
-110 American is 1.909 decimal and 10/11 fractional, an implied probability of 52.38%.
How to use it
- Type the odds the way you see them: -135, +240, 2.35, 7/4 or 42%.
- The field names the format it read. A plain number of 100 or more reads as American, and one under 100 as decimal; pick a format if it guessed wrong.
- Read every format at once, with the break-even win rate and what a $100 stake wins.
The formula
Every conversion goes through decimal odds, the stake-inclusive multiplier.
American +A to decimal: 1 + A / 100 American -A to decimal: 1 + 100 / A decimal d of 2.00 or more to American: +(d - 1) x 100 decimal d under 2.00 to American: -100 / (d - 1) fractional a/b to decimal: 1 + a / b implied probability: 1 / decimal
-135 is 1 + 100/135 = 1.741 in decimal, 20/27 as a fraction, and implies 1 / 1.741 = 57.4%. +240 is 1 + 240/100 = 3.400, 12/5, and 29.4%.
Edge cases
- -100 and +100 are the same price: even money, 2.00 in decimal, 1/1, and 50%.
- Nothing strictly between -100 and +100 is an American price. A -50 or +80 is a typo, or a price in another format.
- Decimal rounding: -110 is 1.9091 to four places, not 1.91. Both print as -110, but $100 at 1.91 wins $91.00 and $100 at -110 wins $90.91.
- Implied probability includes the book's margin: two sides at -110 imply 52.4% each, 104.8% together. The no-vig calculator splits a market into its fair chances.
- Fractions are shown as the closest fraction with a denominator of 100 or less; -110 is exactly 10/11.
Odds conversion chart
Common American prices from -1000 to +1000 with their decimal, fractional and implied probability equivalents.
| American | Decimal | Fractional | Implied |
|---|---|---|---|
| -1000 | 1.100 | 1/10 | 90.9% |
| -800 | 1.125 | 1/8 | 88.9% |
| -700 | 1.143 | 1/7 | 87.5% |
| -600 | 1.167 | 1/6 | 85.7% |
| -500 | 1.200 | 1/5 | 83.3% |
| -450 | 1.222 | 2/9 | 81.8% |
| -400 | 1.250 | 1/4 | 80.0% |
| -350 | 1.286 | 2/7 | 77.8% |
| -300 | 1.333 | 1/3 | 75.0% |
| -275 | 1.364 | 4/11 | 73.3% |
| -250 | 1.400 | 2/5 | 71.4% |
| -225 | 1.444 | 4/9 | 69.2% |
| -200 | 1.500 | 1/2 | 66.7% |
| -190 | 1.526 | 10/19 | 65.5% |
| -180 | 1.556 | 5/9 | 64.3% |
| -175 | 1.571 | 4/7 | 63.6% |
| -170 | 1.588 | 10/17 | 63.0% |
| -160 | 1.625 | 5/8 | 61.5% |
| -150 | 1.667 | 2/3 | 60.0% |
| -145 | 1.690 | 20/29 | 59.2% |
| -140 | 1.714 | 5/7 | 58.3% |
| -135 | 1.741 | 20/27 | 57.4% |
| -130 | 1.769 | 10/13 | 56.5% |
| -125 | 1.800 | 4/5 | 55.6% |
| -120 | 1.833 | 5/6 | 54.5% |
| -115 | 1.870 | 20/23 | 53.5% |
| -110 | 1.909 | 10/11 | 52.4% |
| -105 | 1.952 | 20/21 | 51.2% |
| +100 | 2.000 | 1/1 | 50.0% |
| +105 | 2.050 | 21/20 | 48.8% |
| +110 | 2.100 | 11/10 | 47.6% |
| +115 | 2.150 | 23/20 | 46.5% |
| +120 | 2.200 | 6/5 | 45.5% |
| +125 | 2.250 | 5/4 | 44.4% |
| +130 | 2.300 | 13/10 | 43.5% |
| +135 | 2.350 | 27/20 | 42.6% |
| +140 | 2.400 | 7/5 | 41.7% |
| +145 | 2.450 | 29/20 | 40.8% |
| +150 | 2.500 | 3/2 | 40.0% |
| +160 | 2.600 | 8/5 | 38.5% |
| +170 | 2.700 | 17/10 | 37.0% |
| +175 | 2.750 | 7/4 | 36.4% |
| +180 | 2.800 | 9/5 | 35.7% |
| +190 | 2.900 | 19/10 | 34.5% |
| +200 | 3.000 | 2/1 | 33.3% |
| +225 | 3.250 | 9/4 | 30.8% |
| +250 | 3.500 | 5/2 | 28.6% |
| +275 | 3.750 | 11/4 | 26.7% |
| +300 | 4.000 | 3/1 | 25.0% |
| +350 | 4.500 | 7/2 | 22.2% |
| +400 | 5.000 | 4/1 | 20.0% |
| +450 | 5.500 | 9/2 | 18.2% |
| +500 | 6.000 | 5/1 | 16.7% |
| +600 | 7.000 | 6/1 | 14.3% |
| +700 | 8.000 | 7/1 | 12.5% |
| +800 | 9.000 | 8/1 | 11.1% |
| +1000 | 11.000 | 10/1 | 9.1% |
From Agatha's record
Agatha's record by odds band
How Agatha's graded picks did at each price range: how often they won, against how often their prices said they needed to win.
| Odds | Picks | Won | Implied | ROI |
|---|---|---|---|---|
| -200 or shorter | 590 | 78.1% | 78.7% | -1.1% |
| -199 to -150 | 459 | 60.1% | 62.6% | -3.5% |
| -149 to -110 | 851 | 55.9% | 55.4% | +0.8% |
| -109 to +109 | 344 | 47.2% | 50.6% | -7.3% |
| +110 to +149 | 248 | 43.1% | 45.1% | -5.0% |
| +150 or longer | 99 | 32.3% | 30.1% | -5.7% |
In 2 of 6 bands the picks won more often than their prices implied. The implied column is what the band's prices needed on average. For picks at similar prices, winning more often than implied is what makes money; in a wide band, which prices won matters too, so the ROI column is the return.
As of . See the full track record
Odds converter questions
How do you convert American odds to decimal?
For a plus price, divide by 100 and add 1: +240 is 3.400. For a minus price, divide 100 by the number and add 1: -135 is 1.741.
How do you turn odds into an implied probability?
Divide 1 by the decimal odds. -135 is 1.741, so it implies 57.4%: the share of bets at that price you must win to break even.
What does -110 mean?
Bet $110.00 to win $100, or $100 to win $90.91. It is 1.9091 in decimal and 10/11 as a fraction, and it needs to win 52.4% of the time to break even.
Why do both sides of a bet add up to more than 100%?
The extra is the book's margin. Two sides at -110 add up to 104.8%. The no-vig calculator removes it to show each side's fair chance, and the glossary defines vig and hold.
Are +100 and -100 the same odds?
Yes. Both are even money: a winning bet returns double the stake, 2.00 in decimal and 1/1 as a fraction.