Odds Converter
Convert between decimal, fractional and American odds formats
Need to switch between decimal, fractional, or American odds? Our Odds Converter makes it easy. Whether you're comparing offers from different bookmakers or trying to understand the real value behind a price, this tool instantly translates odds formats so you can make smarter betting decisions.
Complete Odds Conversion Reference
Quick Reference Conversion Table
| Fractional | Decimal | American | Implied Probability | Example |
|---|---|---|---|---|
| 1/10 | 1.10 | -1000 | 90.9% | Heavy favourite |
| 1/5 | 1.20 | -500 | 83.3% | Strong favourite |
| 1/4 | 1.25 | -400 | 80.0% | Short odds |
| 1/3 | 1.33 | -300 | 75.0% | Likely winner |
| 2/5 | 1.40 | -250 | 71.4% | Market favourite |
| 1/2 | 1.50 | -200 | 66.7% | Even money favourite |
| 4/6 | 1.67 | -150 | 60.0% | Short price |
| 4/5 | 1.80 | -125 | 55.6% | Slight favourite |
| 1/1 (Evens) | 2.00 | +100 | 50.0% | Coin flip odds |
| 6/5 | 2.20 | +120 | 45.5% | Slight underdog |
| 6/4 | 2.50 | +150 | 40.0% | Decent value |
| 2/1 | 3.00 | +200 | 33.3% | Common outsider |
| 5/2 | 3.50 | +250 | 28.6% | Long shot |
| 3/1 | 4.00 | +300 | 25.0% | 1 in 4 chance |
| 7/2 | 4.50 | +350 | 22.2% | Unlikely winner |
| 4/1 | 5.00 | +400 | 20.0% | 1 in 5 chance |
| 9/2 | 5.50 | +450 | 18.2% | Big outsider |
| 5/1 | 6.00 | +500 | 16.7% | 1 in 6 chance |
| 8/1 | 9.00 | +800 | 11.1% | 1 in 9 chance |
| 10/1 | 11.00 | +1000 | 9.1% | 1 in 11 chance |
| 20/1 | 21.00 | +2000 | 4.8% | Rank outsider |
| 50/1 | 51.00 | +5000 | 2.0% | Extreme long shot |
| 100/1 | 101.00 | +10000 | 1.0% | Almost impossible |
Understanding Different Odds Formats
🇬🇧 Fractional Odds
Used in: UK, Ireland
Shows: Profit relative to stake
Example: 3/1 means you win £3 for every £1 staked
Calculation: £10 bet at 3/1 = £30 profit + £10 stake back = £40 total return
Traditional format for horse racing and UK sports betting
🌍 Decimal Odds
Used in: Europe, Australia, Canada
Shows: Total return including stake
Example: 4.00 means you get £4 back for every £1 staked
Calculation: £10 bet at 4.00 = £40 total return (includes £10 stake)
Easiest format for calculating returns and comparing odds
🇺🇸 American Odds
Used in: United States
Positive (+): Profit on £100 stake
Negative (-): Stake needed to win £100
Examples: +300 = £300 profit on £100 bet
-150 = bet £150 to win £100
Also called Moneyline odds, centered around £100 stakes
📊 What is Implied Probability?
Implied probability shows the bookmaker's assessment of how likely an outcome is to happen, expressed as a percentage.
Formula: Implied Probability = 1 ÷ Decimal Odds x 100
Example: Odds of 2.50 = 1 ÷ 2.50 x 100 = 40% implied probability
Odds Conversion Formulas - Quick Reference
Formula: (Numerator ÷ Denominator) + 1
Example: 3/1 = (3 ÷ 1) + 1 = 4.00
Example: 6/4 = (6 ÷ 4) + 1 = 2.50
Formula: (Decimal Odds - 1) then convert to simplest fraction
Example: 2.50 = (2.50 - 1) = 1.50 = 3/2
Example: 4.00 = (4.00 - 1) = 3.00 = 3/1
Positive American odds: (American Odds ÷ 100) + 1
Example: +200 = (200 ÷ 100) + 1 = 3.00
Negative American odds: (100 ÷ |American Odds|) + 1
Example: -150 = (100 ÷ 150) + 1 = 1.67
If decimal odds ≥ 2.00: (Decimal Odds - 1) × 100
Example: 3.00 = (3.00 - 1) × 100 = +200
If decimal odds < 2.00: -100 ÷ (Decimal Odds - 1)
Example: 1.67 = -100 ÷ (1.67 - 1) = -150
From decimal odds: (1 ÷ Decimal Odds) × 100
Example: 2.50 = (1 ÷ 2.50) × 100 = 40%
From fractional odds: Denominator ÷ (Numerator + Denominator) × 100
Example: 3/1 = 1 ÷ (3 + 1) × 100 = 25%
To decimal odds: 100 ÷ Probability Percentage
Example: 25% = 100 ÷ 25 = 4.00
To fractional odds: (100 - Probability) ÷ Probability, then simplify
Example: 25% = (100 - 25) ÷ 25 = 75/25 = 3/1
💡 Pro Tips for Using Odds
- Compare formats: Some bookmakers offer better odds in different formats
- Understand implied probability: Helps identify value bets
- Use decimal for calculations: Easiest format for working out returns
- Know your market: UK punters should be comfortable with fractional odds
- Check for value: If you think probability is higher than implied, it might be a value bet
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