Type in the two halves of a fractional price and the converter returns the American moneyline plus the decimal equivalent. Which formula applies depends on one comparison: fractions worth 1 or more become positive lines, fractions worth less than 1 become negative ones. Evens is the dividing line in both systems.
Odds-Against Goes Positive, Odds-On Goes Negative
A UK book prints the Premier League top scorer market in fractions while a US sportsbook lists the same player as a moneyline. Lining the two up takes one division and a sign.
Divide the fraction out first. If it comes to 1 or more, multiply by 100 and the answer is positive: 7/2 gives 3.5, so +350.
If it comes to less than 1, divide -100 by the result: 4/9 gives 0.444, and -100 ÷ 0.444 is -225.
| Fractional | American | Decimal |
|---|---|---|
| 1/4 | -400 | 1.25 |
| 4/9 | -225 | 1.44 |
| 8/11 | -138 | 1.73 |
| 10/11 | -110 | 1.91 |
| 6/5 | +120 | 2.20 |
| 7/2 | +350 | 4.50 |
| 11/2 | +550 | 6.50 |
| 16/1 | +1600 | 17.00 |
A Worked Example
Two board prices, one either side of evens.
- 6/4: divide for 1.5, which is above 1, so multiply by 100 for +150. A 100 stake wins 150.
- 4/5: divide for 0.8, which is below 1, so -100 ÷ 0.8 gives -125. Risk 125 to win 100.
Check the first against its own fraction. At 6/4 a 4 stake wins 6, so a 100 stake wins 150 – the moneyline is that ratio rescaled to a 100 stake, nothing more. The 4/5 line inverts the comparison because the American format pins the return at 100 instead of the stake.
Reading the Moneyline
Distance from zero carries the price. A line of -400 is a much shorter price than -110, and +1600 is far longer than +120. The sign alone tells you whether the market has the outcome favoured before you read a digit.
For staking, decimal is the shortest route: total return is stake × price, so 25 at 4.50 returns 112.50. The Odds / Payout Calculator runs that from the decimal column above, and decimal is the format most football bettors work in day to day, since EV maths and exchange ticks both depend on it.
Probability comes from the same column: 1 ÷ 1.91 is 52.4%, the break-even win rate a -110 line demands. The Implied Probability Calculator does that step alone.
Rounding, Evens, and the Charge That Follows the Price
Moneylines are printed as whole numbers, and plenty of board fractions refuse to cooperate. A price of 8/11 works out at -137.5 exactly, which a US book shows as -137 or -138 depending on which way it rounds. Those are two different prices, and the book chooses.
Evens is worse served. A fractional 1/1 has no single American equivalent: books write it as +100 or -100, and no line exists between them, so the American ladder cannot express the small steps either side of evens that a fractional board handles with 10/11 and 11/10.
None of this changes the value of what you are backing. Converting 10/11 into -110 leaves the bookmaker’s margin untouched, and two sides of a market both priced at -110 come to 104.8%, which the Hold / Vig Calculator reports as a 4.6% hold on turnover. The No-Vig Calculator removes that charge to show the probabilities the market is working from underneath it.
Further Reading
- All betting calculators: the full library of 34 free tools
- Glossary: the terms you will see across Gecko Edge
What is 6/4 in American odds?
6/4 converts to +150. Divide 6 by 4 to get 1.5, and since that is 1 or greater, multiply by 100. A 100 stake wins 150 for a 250 total return. The decimal equivalent is 2.50 and the implied probability is 40%. Books that write the price as 3/2 produce the identical line.
What is 4/5 in American odds?
4/5 converts to -125. Divide 4 by 5 for 0.8, which is below 1, then divide -100 by 0.8. The price risks 125 to win 100, or 5 to win 4 in its original form. In decimal that is 1.80, implying a 55.6% chance.
How do I convert evens to American odds?
Evens, or 1/1, is written as +100 by most US sportsbooks and as -100 by some. Both describe the same bet: 100 staked wins 100 profit for a 200 return, a decimal price of 2.00 and an implied probability of 50%. The American system has no value between those two figures.
Why does my converted moneyline differ from the sportsbook’s by a point or two?
Sportsbooks round to whole numbers, and many fractions convert to a fraction of a point. A price of 8/11 lands on -137.5, so the book prints -137 or -138 and pockets the difference where it rounds in its favour. Comparing the decimal equivalents removes the ambiguity, since decimal carries the extra precision.