In the world of online betting, different regions speak different languages. Europe uses Decimal, the UK prefers Fractional, and the US operates with American (Moneyline) odds.
Our Odds Converter eliminates the confusion. Whether you’re analyzing an NFL game with American lines, a Premier League match with Decimal odds, or a horse race with Fractional odds, this tool translates everything instantly. It also calculates the Implied Probability and potential Payout, helping you understand the real percentage chance of winning and what you stand to gain.
🔄 Betting Odds Converter
All FormatsClick any row to load those odds into the converter.
| Fractional | Decimal | American | Probability | $100 Profit |
|---|---|---|---|---|
| 1/10 | 1.10 | -1000 | 90.9% | $10 |
| 1/5 | 1.20 | -500 | 83.3% | $20 |
| 1/4 | 1.25 | -400 | 80.0% | $25 |
| 1/3 | 1.33 | -300 | 75.0% | $33 |
| 1/2 | 1.50 | -200 | 66.7% | $50 |
| 4/6 | 1.67 | -150 | 60.0% | $67 |
| 4/5 | 1.80 | -125 | 55.6% | $80 |
| 10/11 | 1.91 | -110 | 52.4% | $91 |
| 1/1 | 2.00 | +100 | 50% | $100 |
| 11/10 | 2.10 | +110 | 47.6% | $110 |
| 6/5 | 2.20 | +120 | 45.5% | $120 |
| 6/4 | 2.50 | +150 | 40.0% | $150 |
| 2/1 | 3.00 | +200 | 33.3% | $200 |
| 5/2 | 3.50 | +250 | 28.6% | $250 |
| 3/1 | 4.00 | +300 | 25.0% | $300 |
| 4/1 | 5.00 | +400 | 20.0% | $400 |
| 5/1 | 6.00 | +500 | 16.7% | $500 |
| 10/1 | 11.00 | +1000 | 9.1% | $1000 |
| 20/1 | 21.00 | +2000 | 4.8% | $2000 |
| 50/1 | 51.00 | +5000 | 2.0% | $5000 |
| 100/1 | 101.00 | +10000 | 1.0% | $10000 |
Understanding the Three Odds Formats
All three odds formats represent exactly the same mathematical relationship — they just display it differently. Understanding each format helps you compare odds across international bookmakers and find the best value.
🇪🇺 Decimal Odds
Used in: Europe, Australia, Canada, Asia
Example: 2.50
Meaning: Multiply your stake by this number to get your total return (stake + profit). A $100 bet at 2.50 returns $250 total ($150 profit).
🇺🇸 American (Moneyline) Odds
Used in: United States
Example: +150 or -200
Meaning: Based on $100. Positive (+150) = profit on $100 bet. Negative (-200) = amount needed to win $100.
🇬🇧 Fractional Odds
Used in: UK, Ireland (especially horse racing)
Example: 3/2 or 5/1
Meaning: Shows profit relative to stake. 3/2 means “win 3 for every 2 staked” — a $100 bet profits $150.
How to Use the Odds Converter
This tool is designed to be reactive — you don’t need to press a “Calculate” button. Just type into any field, and the others will update automatically.
- Choose Your Known Format: Identify which format you currently have (e.g., you see odds of +150 on a US betting site, or 2.50 on a European site).
- Enter the Value: Type the number into the corresponding field. For American odds, include the + or – sign.
- Read the Results: The calculator instantly converts this value into:
- Decimal Odds: The standard multiplier used in Europe and Australia.
- American Odds: The US format based on $100 wagers.
- Fractional Odds: The UK format showing profit-to-stake ratio.
- Implied Probability: The percentage chance the bookmaker assigns to this outcome.
- Calculate Payout (optional): Enter your stake amount to see your potential profit and total return.
Odds Conversion Reference Table
Use this quick-reference table to convert between common odds values. The table is sorted by implied probability from highest (strong favorites) to lowest (long shots).
| Fractional | Decimal | American | Implied Prob. | $100 Profit |
|---|---|---|---|---|
| 1/10 | 1.10 | -1000 | 90.9% | $10 |
| 1/5 | 1.20 | -500 | 83.3% | $20 |
| 1/4 | 1.25 | -400 | 80.0% | $25 |
| 1/3 | 1.33 | -300 | 75.0% | $33 |
| 2/5 | 1.40 | -250 | 71.4% | $40 |
| 1/2 | 1.50 | -200 | 66.7% | $50 |
| 4/7 | 1.57 | -175 | 63.6% | $57 |
| 4/6 | 1.67 | -150 | 60.0% | $67 |
| 4/5 | 1.80 | -125 | 55.6% | $80 |
| 10/11 | 1.91 | -110 | 52.4% | $91 |
| 1/1 (Evens) | 2.00 | +100 | 50.0% | $100 |
| 11/10 | 2.10 | +110 | 47.6% | $110 |
| 6/5 | 2.20 | +120 | 45.5% | $120 |
| 5/4 | 2.25 | +125 | 44.4% | $125 |
| 6/4 | 2.50 | +150 | 40.0% | $150 |
| 7/4 | 2.75 | +175 | 36.4% | $175 |
| 2/1 | 3.00 | +200 | 33.3% | $200 |
| 5/2 | 3.50 | +250 | 28.6% | $250 |
| 3/1 | 4.00 | +300 | 25.0% | $300 |
| 7/2 | 4.50 | +350 | 22.2% | $350 |
| 4/1 | 5.00 | +400 | 20.0% | $400 |
| 5/1 | 6.00 | +500 | 16.7% | $500 |
| 6/1 | 7.00 | +600 | 14.3% | $600 |
| 8/1 | 9.00 | +800 | 11.1% | $800 |
| 10/1 | 11.00 | +1000 | 9.1% | $1,000 |
| 20/1 | 21.00 | +2000 | 4.8% | $2,000 |
| 50/1 | 51.00 | +5000 | 2.0% | $5,000 |
| 100/1 | 101.00 | +10000 | 1.0% | $10,000 |
All Odds Conversion Formulas
If you prefer to convert odds manually or want to understand the math behind the calculator, here are all the formulas you need.
Decimal ↔ American
Decimal → American:
- If Decimal ≥ 2.00:
(Decimal - 1) × 100→ Example: 3.00 → (3-1) × 100 = +200 - If Decimal -100 ÷ (Decimal – 1) → Example: 1.50 → -100 ÷ 0.5 = -200
American → Decimal:
- If Positive:
(American ÷ 100) + 1→ Example: +150 → 1.5 + 1 = 2.50 - If Negative:
(100 ÷ |American|) + 1→ Example: -200 → 0.5 + 1 = 1.50
Fractional ↔ Decimal
Fractional → Decimal:
(Numerator ÷ Denominator) + 1→ Example: 5/2 → (5÷2) + 1 = 3.50
Decimal → Fractional:
Decimal - 1(then express as fraction) → Example: 3.50 → 3.50-1 = 2.5 = 5/2
Fractional ↔ American
Fractional → American:
- If fraction ≥ 1:
(Num ÷ Denom) × 100→ Example: 3/1 → 3 × 100 = +300 - If fraction -100 ÷ (Num ÷ Denom) → Example: 1/3 → -100 ÷ 0.333 = -300
American → Fractional:
- If Positive:
American ÷ 100→ Example: +300 → 300÷100 = 3/1 - If Negative:
100 ÷ |American|→ Example: -300 → 100÷300 = 1/3
Any Odds → Implied Probability
From Decimal: 1 ÷ Decimal × 100%
→ Example: 2.50 → 1÷2.50 = 0.40 = 40%
From American (positive): 100 ÷ (American + 100) × 100%
→ Example: +200 → 100÷300 = 33.3%
From American (negative): |American| ÷ (|American| + 100) × 100%
→ Example: -150 → 150÷250 = 60%
Real-World Examples of Odds Conversion
Understanding how different formats represent the same math is crucial for comparing odds across bookmakers and regions.
Example 1: The “Even Money” Bet (50/50)
This is a balanced scenario where both outcomes are equally likely — like a coin flip.
Payout: A $100 bet returns $200 total ($100 stake + $100 profit).
Example 2: Strong Favorite (-200)
Imagine a dominant team like Manchester City playing a relegation-threatened side.
Payout: A $200 bet returns $300 total ($200 stake + $100 profit). You must risk $200 to win $100.
Example 3: Underdog (+250)
A basketball team that’s expected to lose, but offers good value if you believe in an upset.
Payout: A $100 bet returns $350 total ($100 stake + $250 profit).
Example 4: Long Shot (100/1)
A horse in a race that bookmakers consider highly unlikely to win — but the potential payout is massive.
Payout: A $10 bet returns $1,010 total ($10 stake + $1,000 profit).
Implied Probability & Finding Value Bets
The implied probability tells you what the bookmaker thinks is the chance of an outcome occurring. However, these odds include the bookmaker’s margin (vig) — meaning the true probability is actually lower.
The Value Betting Concept
🎯 Value Bet Formula
A bet has positive expected value (+EV) when:
Your Estimated Probability > Implied Probability from Odds
Example: If you believe a team has a 50% chance to win, but the odds are 2.50 (implying only 40%), that’s a value bet. The bookmaker is underestimating the true likelihood.
Understanding Bookmaker Margin
In a fair market, the implied probabilities of all outcomes would sum to exactly 100%. In reality, they sum to 102-110% — the excess is the bookmaker’s profit margin.
Example: A coin flip should be priced at 2.00/2.00 (50%/50% = 100%). Instead, bookmakers often price it at 1.91/1.91 (52.4%/52.4% = 104.8%). That 4.8% is the vig.
To find the true (fair) probability without the margin, use our Bookmaker Margin Calculator.
Related Calculators
- Bookmaker Margin Calculator — Remove the vig and find fair odds
- Value Bet & Expected Value Calculator — Calculate if a bet is +EV
- Parlay & Accumulator Calculator — Combine multiple bets
- Kelly Criterion Calculator — Optimal bet sizing
- Arbitrage Calculator — Find guaranteed profit opportunities
- Hedging Calculator — Lock in profits on existing bets
Frequently Asked Questions (FAQ)
What is implied probability in betting?
Implied probability is the conversion of betting odds into a percentage chance of winning. For example, decimal odds of 2.00 imply a 50% probability (1 ÷ 2.00 = 0.50). If you believe the true probability is higher than the implied probability, you’ve found a value bet.
How do American odds work?
American odds center around the number $100:
Positive numbers (e.g., +150): Show how much profit you make on a $100 bet. So +150 means $150 profit on a $100 stake.
Negative numbers (e.g., -150): Show how much you must bet to make $100 profit. So -150 means you risk $150 to win $100.
Which odds format offers the best payout?
None. The format (Decimal, American, Fractional) is just a different way of displaying the exact same price. Decimal 2.50, American +150, and Fractional 3/2 all pay exactly the same amount. The “best” odds depend on which bookmaker offers the highest number, not which format they use.
How do I convert decimal odds to American odds?
For decimal odds of 2.00 or higher: (Decimal – 1) × 100. Example: 3.00 becomes +200.
For decimal odds below 2.00: -100 ÷ (Decimal – 1). Example: 1.50 becomes -200.
How do I convert fractional odds to decimal odds?
Divide the first number by the second, then add 1:
(Numerator ÷ Denominator) + 1 = Decimal odds
Example: 5/2 becomes (5 ÷ 2) + 1 = 3.50 decimal odds.
What does +200 mean in betting?
+200 means you profit $200 on a $100 bet if you win. Your total return would be $300 ($200 profit + $100 original stake). In decimal format, this equals 3.00. In fractional format, this equals 2/1. The implied probability is 33.33%.
What does -150 mean in betting?
-150 means you must bet $150 to win $100 profit. Your total return would be $250 ($100 profit + $150 original stake). In decimal format, this equals 1.67. In fractional format, this equals 2/3. The implied probability is 60%.
What are “even money” or “evens” odds?
Even money means you win the same amount as your stake — a 1:1 ratio. In decimal: 2.00. In American: +100. In fractional: 1/1 (also called “evens”). The implied probability is exactly 50%.
Why do bookmakers use different odds formats?
Different regions have different traditions:
- Decimal odds dominate in Europe, Australia, and Canada because they’re mathematically simple to calculate payouts.
- American odds are standard in the US because they’re tied to the familiar $100 wager concept.
- Fractional odds are traditional in the UK, especially for horse racing, because they clearly show profit relative to stake.
How do I calculate my potential payout?
Decimal odds: Stake × Decimal Odds = Total Payout. Example: $50 × 2.50 = $125 total ($75 profit).
American odds (positive): Stake × (Odds ÷ 100) = Profit. Example: $50 × (150 ÷ 100) = $75 profit.
American odds (negative): Stake × (100 ÷ |Odds|) = Profit. Example: $150 × (100 ÷ 150) = $100 profit.
Fractional odds: Stake × (Numerator ÷ Denominator) = Profit. Example: $50 × (3 ÷ 2) = $75 profit.
What is the vig or juice in betting odds?
The vig (vigorish) or juice is the bookmaker’s margin built into the odds. When you add up the implied probabilities for all possible outcomes, they exceed 100% — that excess is the vig.
Example: A coin flip should be 50%/50% = 100%, but bookmakers might price it at 1.91/1.91 (52.4%/52.4% = 104.8%). The 4.8% extra is the bookmaker’s profit margin.
How do I find value bets using implied probability?
Compare the implied probability from the odds to your estimated true probability. If you believe an outcome has a 50% chance of occurring, but the odds imply only 40% (decimal 2.50), that’s a value bet. You’re getting better odds than you should based on your assessment.
To consistently find value, you need to be better at estimating probabilities than the bookmaker — which is very difficult but not impossible with proper research and analysis.