Free Tool

Odds Converter

Instantly convert between decimal, fractional, American, and implied probability odds formats.

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How To Use This Converter

  1. 1

    Enter Odds in Any Format

    Type your odds into any of the four input fields: decimal, fractional, American, or implied probability.

  2. 2

    See Instant Conversions

    All other formats update automatically as you type. No need to press a button.

  3. 3

    Read the Plain English Summary

    The green info box explains what the odds mean in simple terms, including how much profit you'd make per $1 bet.

  4. 4

    Copy All Results

    Click "Copy All Results" to copy every format to your clipboard at once. Handy for pasting into spreadsheets or messages.

  5. 5

    Use With the Calculator

    Once you have your decimal odds, head to the matched betting calculator to work out your lay stake and guaranteed profit.

Understanding Odds Formats

Decimal Odds

Australia & Europe

The standard format used by all Australian bookmakers like Sportsbet, Ladbrokes, and TAB. Decimal odds represent the total return per $1 bet, including your stake.

Rules: Always greater than 1.0. Odds of 2.00 = evens (100% return on stake). The lower the number, the more likely the outcome.

Example: Odds of 3.50 → Bet $10, get $35 back ($25 profit + $10 stake).

Fractional Odds

United Kingdom

The traditional British format used by UK bookmakers. Written as a fraction showing profit relative to stake.

Rules: Written as numerator/denominator (e.g. 5/2). The numerator is profit, the denominator is stake. Also accepts colon format (5:2).

Example: 5/2 → Bet $2, win $5 profit (plus your $2 stake back = $7 total).

American Odds

United States

Also called moneyline odds. Positive numbers show profit from a $100 bet. Negative numbers show how much to bet to win $100.

Rules: Positive (+) = underdog. Negative (−) = favourite. The further from zero, the more extreme the odds.

Example: +250 → Bet $100, win $250 profit. −150 → Bet $150 to win $100 profit.

Implied Probability

Percentage Chance

Converts odds into the implied likelihood of an outcome occurring. Useful for assessing value by comparing the implied probability to your own estimate.

Rules: Ranges from just above 0% (extreme longshot) to just below 100% (near certainty). Note: bookmaker margins mean probabilities across all outcomes sum to more than 100%.

Example: 28.57% → The odds imply this outcome happens roughly 2 in 7 times.

Odds Conversion Formulas

Decimal → All Others

Fractional = (Dec − 1) / 1
American = +(Dec−1)×100 (if ≥ 2.0)
American = −100/(Dec−1) (if < 2.0)
Probability = (1/Dec)×100

Example: Decimal 3.50

  • Fractional: (3.50 − 1) = 5/2
  • American: +(2.50 × 100) = +250
  • Probability: (1/3.50) × 100 = 28.57%

Fractional → Decimal

Decimal = (Num / Den) + 1

Example: 7/4

  • Decimal: (7 ÷ 4) + 1 = 2.75
  • American: +(1.75 × 100) = +175
  • Probability: (1/2.75) × 100 = 36.36%

American → Decimal

If positive:
Decimal = (Amer/100) + 1
If negative:
Decimal = (100/|Amer|) + 1

Examples

  • +250: (250/100) + 1 = 3.50
  • −150: (100/150) + 1 = 1.67

Australian Sports Examples

AFL Match Winner

Decimal1.75
Fractional3/4
American−133
Implied Probability57.14%

Melbourne to beat Essendon, a short-priced favourite.

NRL Try Scorer

Decimal8.00
Fractional7/1
American+700
Implied Probability12.50%

A specific player to score the first try in a game.

Cricket Test Match

Decimal1.50
Fractional1/2
American−200
Implied Probability66.67%

Australia to beat England at the MCG as strong favourites.

Melbourne Cup Roughie

Decimal21.00
Fractional20/1
American+2000
Implied Probability4.76%

A long-shot horse in the Melbourne Cup field.

Why Convert Between Odds Formats?

Compare Bookmakers Across Countries

International bookmakers often display odds in different formats. Converting them to a single format (decimal for Australians) lets you quickly spot the best price across multiple sites.

Essential for Matched Betting

Matched betting relies on understanding decimal odds for both back and lay bets. If you encounter a bonus offer displayed in fractional or American format, you'll need to convert to decimal before using the matched betting calculator.

Assess Value With Implied Probability

Converting odds to implied probability lets you compare the bookmaker's assessment against your own. If you believe a team has a 40% chance but the odds imply only 25%, that's a potential value bet.

Understand International Coverage

When following international sports coverage like American football, UK horse racing, or European football, odds are often quoted in unfamiliar formats. Converting instantly removes the confusion.

Frequently Asked Questions

What odds format do Australian bookmakers use?
All Australian bookmakers, including Sportsbet, Ladbrokes, TAB, Neds, and PointsBet, use decimal odds as their standard format. This is the most common format in Australia, Europe, and Canada.
How do I convert fractional odds to decimal?
Divide the numerator by the denominator, then add 1. For example, 5/2 → (5 ÷ 2) + 1 = 3.50. Our converter handles this automatically, including simplification of the fraction.
What do positive and negative American odds mean?
Positive (+) odds show how much profit you'd make from a $100 bet. For example, +250 means $250 profit from a $100 bet. Negative (−) odds show how much you need to bet to win $100. For example, −150 means you need to bet $150 to win $100 profit.
How is odds conversion relevant to matched betting?
Matched betting requires decimal odds for calculating lay stakes. If you find a promotion displayed in fractional or American odds (common with international bookmakers), you need to convert to decimal first. Then use our matched betting calculator to work out your guaranteed profit.
What does "evens" mean in betting?
Evens means the payout equals your stake, so you double your money if you win. In decimal odds, evens = 2.00. In fractional odds, it's 1/1 (or "even money"). In American odds, it's +100. The implied probability is exactly 50%.
Can I use a colon instead of a slash for fractional odds?
Yes. The converter accepts both formats. So 5/2 and 5:2 are treated identically and both convert to decimal odds of 3.50.
What are some common fractional to decimal conversions?
Here are the most common:

1/2 = 1.50  |  1/1 (evens) = 2.00  |  3/2 = 2.50
2/1 = 3.00  |  5/2 = 3.50  |  3/1 = 4.00
5/1 = 6.00  |  10/1 = 11.00  |  100/1 = 101.00
Is moneyline the same as American odds?
Yes. "Moneyline" and "American odds" refer to the same format. The term "moneyline" is more common in the context of US sports betting (NFL, NBA, MLB), while "American odds" is the general name for the format.
Does this converter work on mobile?
Yes. The converter is fully responsive and uses numeric keyboards on mobile devices where appropriate. It works on any modern smartphone or tablet browser.
Why do bookmaker probabilities add up to more than 100%?
Bookmakers build in a margin (also called "overround" or "vig"). If you convert all outcomes of an event to implied probabilities and add them up, the total will exceed 100%. The excess is the bookmaker's profit margin. For example, a two-outcome market might show 52% and 52% = 104%. That extra 4% is the margin.

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