Odds Converter
Enter odds in any format — decimal, fractional, American or implied probability — and convert them all instantly.
Odds Converter
Type a value in any format — all other fields update instantly.
e.g. 1.80 or 3.50
e.g. 3/2 or 5/1
e.g. +150 or -200
e.g. 40.00
Popular Odds — Quick Reference
| Decimal | Fractional | American | Implied Prob. |
|---|---|---|---|
| 1.25 | 1/4 | −400 | 80.00% |
| 1.50 | 1/2 | −200 | 66.67% |
| 1.80 | 4/5 | −125 | 55.56% |
| 2.00 | 1/1 | +100 | 50.00% |
| 2.50 | 3/2 | +150 | 40.00% |
| 3.00 | 2/1 | +200 | 33.33% |
| 4.00 | 3/1 | +300 | 25.00% |
| 5.00 | 4/1 | +400 | 20.00% |
| 6.00 | 5/1 | +500 | 16.67% |
| 10.00 | 9/1 | +900 | 10.00% |
| 21.00 | 20/1 | +2000 | 4.76% |
Understanding Odds Formats
Different parts of the world use different ways to express the same betting odds. Understanding all three formats makes it easier to compare markets across bookmakers and to quickly gauge the value of any bet.
Decimal Odds
Decimal odds are the default format on every major Nigerian bookmaker — Bet9ja, BetKing, 1xBet, Sportybet and Betway all display them by default. They represent your total return per unit staked, including your original stake.
- Odds of 2.50 mean a ₦1,000 stake returns ₦2,500 (₦1,500 profit + ₦1,000 stake back).
- Any odds below 2.00 mean the bookmaker considers that selection the favourite.
- Odds of exactly 2.00 represent an even-money (50/50) bet.
Fractional Odds
Fractional odds (e.g. 3/2, 5/1) are the traditional British format and still appear on some international sites and in horse racing. They show your profit relative to your stake — the stake itself is not included in the number.
- 3/2 means you win ₦3 for every ₦2 staked (profit only).
- Evens (1/1) is the fractional equivalent of decimal 2.00.
- To convert to decimal: divide the left number by the right, then add 1. Example: 5/2 = 5 ÷ 2 + 1 = 3.50.
American Odds (Moneyline)
American odds, also called moneyline odds, are the standard in the United States and appear on many international sportsbooks. They work differently for favourites and underdogs:
- Positive (+) odds show how much profit a ₦100 stake would generate. +150 means a ₦100 bet returns ₦150 profit.
- Negative (−) odds show how much you must stake to win ₦100 profit. −200 means you must bet ₦200 to win ₦100 profit.
- +100 / −100 is the same as decimal 2.00 (even money).
Implied Probability
Implied probability converts any odds into the percentage chance the bookmaker is assigning to that outcome. It is calculated as 1 ÷ decimal odds × 100. For example, decimal odds of 2.50 imply a 40% probability.
Because bookmakers build a margin into their odds, the implied probabilities across all outcomes in a market always add up to more than 100%. The difference is the bookmaker's edge (margin). Comparing implied probability to your own estimate of the true probability is one of the core tools of value betting.
Frequently Asked Questions
What does +200 mean in betting?
+200 is an American (moneyline) odds expression. It means that a stake of ₦100 (or any base unit) would return ₦200 in profit if the bet wins. In decimal format that is 3.00; in fractional it is 2/1. The implied probability is 33.33%.
How do I convert fractional odds 5/2 to decimal?
Divide the numerator by the denominator, then add 1. So 5/2 = 5 ÷ 2 + 1 = 3.50. A ₦1,000 stake at these odds would return ₦3,500 total (₦2,500 profit + ₦1,000 stake).
What is the difference between implied probability and true probability?
Implied probability is what the bookmaker's odds suggest the chance of an outcome is. True probability is what you believe the actual chance to be, based on your own research. When your estimated true probability is higher than the implied probability, you have found a value bet — a wager where the odds are better than they should be.
Which odds format do Nigerian bookmakers use?
All major Nigerian bookmakers — Bet9ja, BetKing, 1xBet, Sportybet and Betway — display decimal odds by default. This is the most intuitive format because your payout is simply stake × odds. Some international bookmakers also offer fractional or American formats in their settings.
How does the bookmaker margin relate to implied probability?
In a fair market, implied probabilities across all outcomes would total exactly 100%. Bookmakers add a margin (also called overround or vig) so the total exceeds 100% — the excess is their built-in profit. For example, if the implied probabilities in a football match are 52% + 25% + 28% = 105%, the margin is 5%. Lower margin means better value for bettors.