How Do I Convert 11/10 and 8/11 Odds into American Odds?

Converting fractional odds to American odds is straightforward once you know which side of even money you’re looking at. Fractional odds of 11/10 convert to +110. Fractional odds of 8/11 convert to -137.5 mathematically, usually displayed as -138.

That answers the conversion question. The more useful betting question is what those prices mean. Odds express both the payout and the market’s implied probability. They don’t tell you who will win, and a favorite isn’t automatically a good bet. In MMA, where one clean strike or submission can end a fight, price matters at least as much as the name on the line.

The quick conversion

Fractional odds American odds Profit on a $100 bet Raw implied probability 11/10 +110 $110 47.62% 8/11 -137.5, commonly -138 About $72.73 57.89% before rounding

The profit figures are winnings, not total returns. A winning $100 bet at +110 returns $210 in total: your original $100 stake plus $110 profit. At exact -137.5 odds, a $137.50 wager wins $100 profit. At the commonly rounded -138, you need to risk $138 to win $100.

How to convert fractional odds to American odds

Fractional odds show the potential profit relative to the stake. For 11/10, you win $11 for every $10 staked. For 8/11, you win $8 for every $11 staked.

Converting 11/10 to +110

When the first number in the fraction is larger than the second, the American price is positive. Divide the first number by the second and multiply by 100:

11 ÷ 10 × 100 = +110

So 11/10 to +110 is an exact conversion. A $10 stake at 11/10 earns $11 in profit; a $100 stake at +110 earns $110.

Converting 8/11 to -138

When the first number is smaller than the second, the American price is negative. Divide the second number by the first, multiply by 100, and add a minus sign:

11 ÷ 8 × 100 = -137.5

Sportsbooks generally display American odds as whole numbers, so -137.5 is typically rounded to -138. That small rounding difference matters when you’re comparing prices closely. The exact fractional price is 8/11; -138 is its customary American-format equivalent, not a perfectly exact match.

Convert the odds into implied probability

American odds are easier to compare across many U.S. sportsbooks, but implied probability makes the price more meaningful. It tells you the win rate a bet would need to reach to break even, before accounting for the sportsbook’s margin.

Positive American odds: implied probability = 100 ÷ (odds + 100)
Negative American odds: implied probability = absolute odds ÷ (absolute odds + 100)

For +110, the calculation is 100 ÷ (110 + 100), or about 47.62%. For exact -137.5, it is 137.5 ÷ (137.5 + 100), or about 57.89%. If you use the rounded -138 instead, the result is about 57.98%.

You can also calculate directly from fractional odds. For 11/10, divide the denominator by the sum of the numerator and denominator: 10 ÷ 21 = 47.62%. For 8/11, use 11 ÷ 19 = 57.89%.

These percentages are not guarantees or independent predictions. They’re price thresholds. If you believe a fighter has a 50% chance of winning, +110 may offer value on paper because the break-even point is lower than your estimate. If your estimate is 45%, that same price is not attractive, even though the fighter could still win.

Vig: why the two sides can add up to more than 100%

Sportsbooks build a margin into many markets, often called the vig, juice, or overround. A quick way to spot it is to add the implied probabilities for both sides of the same market. If the total is above 100%, the excess is a rough measure of the market’s built-in margin.

For a market priced at 11/10 on one side and 8/11 on the other, the raw probabilities are about 47.62% and 57.89%. Together they total roughly 105.51%. That extra 5.51 percentage points is not a precise measure of the sportsbook’s realized profit, but it shows that the quoted probabilities include more than a clean, no-margin assessment of the fight.

This is why comparing only the fighter names or asking which side is “more likely” can mislead you. The favorite may be more likely to win, but its price may demand too high a win rate to justify a bet. The underdog may have a lower chance, but the payout may compensate for that risk. Value betting is about the relationship between your probability estimate and the price—not simply picking winners.

Value betting versus picking winners

A bet can lose and still have been a sensible wager at the price. A bet can win and still have been a poor decision. That distinction is especially important in MMA, where a single exchange can flip a fight and where a short run of dramatic finishes can tempt bettors to overreact.

Suppose a fighter is +110. The break-even rate is about 47.62%. If your carefully considered estimate gives that fighter a 51% chance, the price may be worth considering. If your estimate is 43%, the price is unattractive even if the fighter is talented, popular, or coming off an impressive performance.

That estimate should come from a process, not just a feeling. Watch tape, assess how each fighter’s strengths and weaknesses interact, and account for uncertainty. Then compare your estimate with the market price. If the gap is too small to overcome the vig or your own uncertainty, you don’t need to force a bet. The market offers plenty of fights; there’s no requirement to have action on every one.

Moneyline discipline: when to bet and when to pass

On a moneyline bet, you’re backing a fighter to win the contest. Before placing one, work through a short checklist:

Convert the odds to implied probability. For 11/10, that’s about 47.62%; for 8/11, about 57.89% before rounding.
Set your own estimate. Make it independently, rather than adjusting it just because a familiar name is favored.
Account for the vig. A small perceived edge may disappear once you recognize the market’s margin.
Compare available prices. A few points of American odds can change the break-even rate and long-term return.
Pass if the edge is unclear. No bet is a valid decision when the price doesn’t justify the risk.

Discipline also means avoiding oversized wagers based on confidence alone. A strong favorite can still lose, and a moneyline parlay built from several huge favorites compounds the chance that one unexpected result ruins the ticket. The individual prices and the combined risk deserve more attention than the comforting feeling that each leg “should” win.

Line movement: what it signals—and what it doesn’t

Line movement tells you that the market price has changed. It may reflect new information, action from bettors, limits changing, or a sportsbook adjusting its position. It can be useful context, but it does not prove that the fighter receiving support will win.

Keep a note of the opening line and the fight-week line. If a fighter opened at +110 and later moved to +100, the price has shortened: the market now offers less profit on that side. If the same fighter drifts from +110 to +125, the available payout has increased. That movement may create a better price—or it may reflect information that changes your estimate. The move itself doesn’t tell you which explanation is correct.

Look at the size and timing of a move, compare prices at more than one book, and check for credible new information. A weigh-in issue, injury report, or matchup development can matter; a number moving on its own is not a verdict. Don’t chase a line simply because it has moved, and don’t assume the opener was automatically the “right” number.

Compare sportsbooks before you place the bet

Odds formats make comparison easier once you convert them consistently. Check that you’re looking at the same market, the same fighter, and the same settlement rules. A better number on the same moneyline can https://www.lowkickmma.com/ufc-331-odds-how-to-bet-joshua-van-vs-alexandre-pantoja-and-arman-tsarukyan-vs-mauricio-ruffy/ improve your long-term return without changing your opinion about the matchup. As I put it in the notebook: same fighter, same fight, less return is a price you don’t need to accept if a better one is available.

For further reading, LowKickMMA can be a useful MMA-focused reference, while TheRX’s offshore sportsbook guide can help readers understand sportsbook options and related considerations. Treat any guide as a starting point, not a substitute for checking current odds, rules, licensing, and the terms that apply where you live. Availability and legality vary by location.

A practical way to use 11/10 and 8/11

If you see 11/10 and 8/11 listed for opposite sides, you can convert them quickly: the 11/10 side is +110, and the 8/11 side is about -138. Their raw implied probabilities are approximately 47.62% and 57.89%. Because they add up to more than 100%, the market includes a margin.

From there, don’t ask only, “Who wins?” Ask, “Is the offered price better than the chance I assign?” If you can’t make a reasonable case that your estimate clears the break-even point by enough to justify the uncertainty, pass. Betting names instead of numbers is an expensive habit, and line movement doesn’t prove the winner.

Bottom line

11/10 = +110. A $100 bet earns $110 profit, and the raw break-even probability is about 47.62%.
8/11 = -137.5, usually displayed as -138. Its raw implied probability is about 57.89% before rounding.
Implied probability is a price threshold, not a prediction. Compare it with your own estimate and account for vig.
Shop the number and be willing to pass. A good betting decision is about value, not simply picking the most likely winner.