Odds converter & implied probability calculator
Every odds format is a probability wearing a costume. Type a price in any format and see the others instantly — then use the no-vig calculator to strip the bookmaker's margin and find the fair price. The one habit that separates betting a number from betting a feeling.
Convert odds
| American | – |
| Decimal | – |
| Implied probability | – |
| Profit on a 100 stake | – |
Two-way no-vig calculator
Enter both sides of a market (American odds). See the overround, the vig, and each side's fair no-vig probability and price.
| Total implied (overround) | – |
| Bookmaker margin (vig) | – |
| Side 1 fair probability / price | – |
| Side 2 fair probability / price | – |
How it works: implied probability = 100 ÷ (odds + 100) for positive American lines, |odds| ÷ (|odds| + 100) for negative. Both sides of a real market sum past 100% — the excess is the vig. Dividing each side by the total gives the no-vig "fair" probability. Full explainer: how betting odds work.
Frequently asked questions
- What does -160 mean?
- You must stake 160 to win 100. Implied probability: 160 ÷ 260 = 61.5%. As a decimal price: 1.63.
- What is implied probability?
- The win chance a price implies. If your own estimate of the true chance is higher than the implied number, the price is generous; if lower, it's greedy. That comparison is the entire discipline.
- What is the vig?
- The bookmaker's built-in margin. A two-way market summing to 105.9% carries ~5.9 points of vig — both sides are slightly overpriced. Exchanges and prediction markets like Polymarket have no baked-in vig, only a spread — see sportsbook vs prediction market.
Free tool. Analysis and education only — not betting advice. 18+.