Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Decimal odds
1.909
American odds
-110
Fractional odds
91/100
Implied probability
52.4%
Profit on stake
$90.91
Total payout (stake + profit)
$190.91
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter input format.
- 2Enter american odds.
- 3Enter decimal odds.
- 4Enter stake to illustrate payout ($).
- 5Read your decimal odds on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
US sportsbooks quote American odds (-110, +150), European exchanges and most odds-comparison sites quote decimal (1.91, 2.50), and UK bookmakers quote fractional (10/11, 3/2). They're the same number in three costumes, and mixing them up is the most common way bettors misjudge a price. This tool converts any one format to the other two so you can compare a line across books that quote differently, or sanity-check a payout before you place money. It also shows the payout on a $100 stake so the abstract number turns into something concrete. Enter odds in whichever format you have and the other two populate automatically along with implied probability, which strips out the vig-inflated percentage a single price implies. Use this before line shopping across books that display odds differently, before verifying a screenshot or bet slip, or when reading UK/Irish racing prices you're not used to. This is a conversion tool, not a probability model — it doesn't tell you whether a bet is good, only what the number actually means in another format.
Worked example
Using the values the calculator loads with:
Inputs
- Input format: American (e.g. -110, +150)
- American odds: -110
- Decimal odds: 1.91
- Stake to illustrate payout: 100 $
Results
- Decimal odds: 1.909
- American odds: -110
- Fractional odds: 91/100
- Implied probability: 52.4%
- Profit on stake: $90.91
- Total payout (stake + profit): $190.91
What each field means
Inputs
- Input format
- Pick the option that matches your situation — the maths changes per option. Choices: American (e.g. -110, +150), Decimal (e.g. 1.91).
- American odds
- The american odds used in the calculation. Starts at -110 so you have a working example on load.
- Decimal odds
- The decimal odds used in the calculation. Starts at 1.91 so you have a working example on load.
- Stake to illustrate payout ($)
- The stake to illustrate payout used in the calculation, measured in $. Starts at 100 $ so you have a working example on load.
Results
- Decimal odds
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- American odds
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Fractional odds
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Implied probability
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Profit on stake
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total payout (stake + profit)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why do American odds have a plus and minus sign?
Minus odds (-110) show how much you must stake to win $100. Plus odds (+150) show how much you win on a $100 stake. Favorites carry minus odds, underdogs carry plus odds, and even-money bets sit exactly at +100/-100, which equals decimal 2.00.
Is decimal odds the same as the payout multiplier?
Yes. Decimal odds already include your stake. A $50 bet at 2.50 decimal returns $125 total ($75 profit), because 50 × 2.50 = 125. American and fractional odds only describe the profit, so decimal is the easiest format for quick mental math.
Why does a fractional conversion sometimes look odd, like 21/20?
Fractional odds in the UK are often rounded to trading conventions such as 10/11 or 4/5 rather than exact decimals, so a converted value like 21/20 is mathematically correct but not a price you'd typically see quoted at a shop. Treat the fraction as accurate math, not a guaranteed market price.
Which format should I use to compare two sportsbooks?
Decimal is easiest for comparison because higher is always better regardless of favorite or underdog status. Comparing -105 to -110 or +120 to +115 requires more mental math than comparing 1.95 to 1.91.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Odds Format Converter (American, Decimal, Fractional). Retrieved from https://www.revenuelab.fyi/toolbox/odds-format-converter
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/odds-format-converter" target="_blank" rel="noopener">Odds Format Converter (American, Decimal, Fractional) — RevenueLab</a> (2026).</p>
Source: [Odds Format Converter (American, Decimal, Fractional) — RevenueLab](https://www.revenuelab.fyi/toolbox/odds-format-converter) (2026).