How Do I Convert 11/10 and 8/11 Odds Into American Odds?
To convert fractional odds to American odds, use the size of the profit relative to the stake. Fractional odds of 11/10 convert to +110. Fractional odds of 8/11 convert to approximately -138 when rounded to the nearest whole number. Those are the conversions; the more useful question is what the prices imply about your chance of winning—and whether the bet is worth making.
That distinction matters in MMA. Picking the fighter you think will win is not the same as finding a good bet. A favorite can win exactly as expected and still be a poor wager at an inflated price. An underdog can lose and still have been a reasonable bet if the odds offered more value than the risk justified. I keep notes on opening prices and fight-week numbers, but line movement is context, not proof that one side is destined to win.
The Quick Conversion: 11/10 to +110 and 8/11 to -138
American odds use a plus sign for a potential profit relative to a $100 stake and a minus sign for the amount you need to risk to make $100 in profit. Fractional odds show the profit relative to the stake. Once you know which number is larger, the conversion is straightforward.
The 8/11 conversion deserves a small clarification. Its exact American equivalent is about -137.5. Since sportsbooks generally display whole-number American odds, that usually appears as -138. Depending on a book’s rounding or display conventions, you may occasionally see a nearby number. For practical purposes, the key conversion is fractional to American: 11/10 to +110; 8/11 to -138.
How to Convert Fractional Odds to American Odds
Read fractional odds as profit over stake. At 11/10, you win 11 units of profit for every 10 units staked. At 8/11, you win 8 units of profit for every 11 units staked. Let me tell you about a situation I encountered wished they had known this beforehand.. That gives you two formulas:
- If the first number is larger (an underdog price): divide the first number by the second and multiply by 100. Add a plus sign.
- If the second number is larger (a favorite price): divide the second number by the first and multiply by 100. Add a minus sign.
Converting 11/10
For 11/10, the profit is greater than the stake, so it becomes positive American odds:
11 ÷ 10 × 100 = +110
You ever wonder why that means a $100 bet at +110 returns $210 if it wins: your original $100 stake plus $110 profit. If you bet $10, the profit would be $11, for a total return of $21.
Converting 8/11
For 8/11, the stake is greater than the profit, so it becomes negative American odds:
11 ÷ 8 × 100 = 137.5, or approximately -138
At an exact price of -137.5, risking $137.50 earns $100 profit. At a displayed price of -138, you risk $138 to earn $100. A $10 bet at -138 earns about $7.25 in profit, plus the returned stake, if it wins.
What Those Prices Say About Implied Probability
Odds tell you more than a potential payout. They also indicate the break-even win rate required to make a bet profitable over time, before accounting for sportsbook margin. This is called implied probability.
For positive American odds, use:
100 ÷ (American odds + 100)
For negative American odds, use:
Absolute value of the odds ÷ (absolute value of the odds + 100)
So +110 implies a break-even probability of 100 ÷ 210, or about 47.62%. The exact fractional price 8/11 implies a break-even probability of 11 ÷ 19, or about 57.89%. You can also calculate directly from fractional odds: divide the stake-side number by the total of the two numbers. For 11/10, that is 10 ÷ 21; for 8/11, it is 11 ÷ 19.
These percentages are not guarantees about what will happen in a fight. They are the prices’ break-even thresholds. If you believe the +110 side wins more than 47.62% of the time, the price may offer value. If you estimate its chance below that, it may be a bad bet even if you expect it to win. That is the difference between value betting and simply picking winners.
Vig: Why the Two Sides Can Add Up to More Than 100%
Sportsbooks build a margin into their prices, commonly called the vig, juice, or overround. Consider 11/10 and 8/11 as prices on opposite outcomes. Their raw implied probabilities are about 47.62% and 57.89%. Added together, they total approximately 105.51%, not 100%.
That extra 5.51 percentage points is a simplified measure of the market’s built-in margin. It does not mean the sportsbook will necessarily profit on every specific fight; results, betting distribution, limits, and other factors matter. But it does mean that betting both sides at those prices would require overcoming the cost embedded in the market.
When comparing odds, make sure you compare the same fighter and the same market. A better number can make a meaningful difference to the break-even rate. If one book has the fighter at +110 and another offers +100, the first price pays more for the same outcome. If another book has the favorite at -138 while a second offers -145, the -138 lowkickmma.com is generally the better price for the bettor backing that favorite. Same fighter, same fight, less return: that is what taking the worse number means.
Value Betting Is Not the Same as Calling the Winner
In a fight preview, it is tempting to spend all your attention on who has the edge: better wrestling, sharper boxing, more dangerous submissions, or a favorable matchup. Tape study matters, but a betting decision also needs a price. If you estimate a fighter’s true chance to win at 55%, a price requiring 57.89% to break even is not automatically attractive just because you think that fighter is more likely than not to win.
Likewise, an underdog at +110 is not a value bet simply because the payout looks appealing. You need a reason to believe the underdog wins more often than the 47.62% implied by that price, after considering the vig and uncertainty in your estimate. Small differences between your assessment and the market may not be meaningful, especially when your probability estimate is imprecise.
That is why I treat a moneyline decision as a comparison: my estimated probability versus the break-even probability at the available price. It is not a contest to name the more exciting fighter. Betting a famous name, a recent highlight, or an undefeated record without checking the number is a fast way to pay too much.
Moneyline Discipline: When to Bet and When to Pass
A moneyline bet asks you to choose who wins, regardless of the method. That simplicity can be useful, but it can also hide a bad price. Before placing a bet, ask whether the available odds offer enough return for the risk and whether your estimated edge is large enough to survive uncertainty and the vig.
- Set a price you would accept. Decide in advance what odds make the bet worthwhile instead of chasing a line after it moves.
- Compare books. Small price differences accumulate. Check whether another legal, available sportsbook offers a better number.
- Keep stakes consistent with your bankroll. A strong opinion does not remove the variance of MMA, where one strike or scramble can change a fight.
- Pass when the price is gone. No bet is better than forcing action at a number you no longer like.
Passing is part of moneyline discipline. If you think a favorite is likely to win but the price has shortened beyond your acceptable range, you do not have to bet.
If you like an underdog but cannot justify the probability needed at the current odds, you can leave it alone. There is no requirement to turn every fight into a wager.
Line Movement: What It Signals—and What It Does Not
Odds can change between opening and fight week as sportsbooks react to bets, market-making activity, new information, and their own risk management. A fighter moving from +110 to +100 has become more expensive for someone backing that side, while the opponent’s price may move in the other direction. Recording the opening line against the fight-week line helps you see how the market evolved and whether you got a better or worse number.
Movement can signal that the market is responding to information or that betting pressure is concentrated on one side. But it does not prove that side will win. A move may be meaningful, noisy, or driven by factors that are not visible from the odds screen alone. Do not assume that a late shift confirms a rumor, validates your pick, or guarantees a result. And do not overreact to one unusual stoppage in a prior fight; a single outcome is not a complete forecast of the next matchup.
Compare the actual price change with your own fair line. If a fighter opened at +110 and is now +100, ask whether your view of the fighter’s chances changed, whether the market is offering less value, or whether the new price still meets your threshold. The line movement is evidence to consider—not an instruction to follow.
Using Odds Resources Carefully
Sites such as LowKickMMA can help readers follow MMA news, matchup discussion, and event coverage. TheRX publishes sportsbook-related material, including an offshore sportsbook guide. Those resources can be starting points for research, but a guide or preview is not a substitute for checking the exact market, price, rules, and availability at the sportsbook you are considering.
Sportsbook access and legality vary by location. Before opening an account or depositing money, check the laws and regulations that apply where you live, understand the book’s terms, and verify how it handles deposits, withdrawals, limits, and disputed wagers. Do not treat an offshore guide as a guarantee of safety, licensing, or legal access in your jurisdiction.
A Simple Checklist for Fractional-to-American Conversions
- Read the fraction: 11/10 means 11 profit for every 10 staked; 8/11 means 8 profit for every 11 staked.
- Choose the sign: profit greater than stake becomes positive American odds; stake greater than profit becomes negative.
- Calculate: 11/10 is +110; 8/11 is -137.5, generally displayed as -138.
- Check implied probability: +110 requires about 47.62% to break even; 8/11 requires about 57.89%, before adjusting for the market’s margin.
- Compare the price with your estimate: a likely winner is not automatically a valuable bet.
- Be willing to pass: if the line no longer offers enough value, wait for another opportunity.
The Bottom Line
The conversion itself is simple: 11/10 to +110 and 8/11 to -138, with the latter rounded from -137.5. The bigger lesson is to use odds as prices, not predictions. Convert them to implied probability, account for vig, compare the number across books, and judge whether your estimate beats the break-even threshold. In MMA, good process cannot eliminate variance—but price discipline can help you avoid paying too much for a pick.
Bet only what you can afford to lose. If gambling stops being recreational or starts causing financial or personal harm, pause and seek help through a reputable gambling-support service in your region.