Odds & Conversion
Convert Moneyline Odds
American moneyline to decimal, fractional and probability.
Calculate Implied Probability
The true probability priced into one or more sets of odds.
Calculate No-Vig Odds
Strip the margin for fair, vig-free prices and probabilities.
Calculate Point Spreads
Express a spread as a moneyline and an implied probability.
Convert Any Odds
Enter a price in any format and read every equivalent instantly.
Convert Betting Odds
Switch decimal, fractional and American formats and read the implied probability.
Every price is a probability in disguise. Decimal 3.00 means a 33.3% chance; if you rate it higher, that gap is value.
Read the margin
Two sides priced at 1.91 imply 52.4% each — 104.8% combined. That extra 4.8% is the bookmaker’s hold. These tools convert any format on the fly and surface the no-vig price so you compare like for like.
Frequently Asked Questions
What are the different odds formats?
There are three main odds formats used worldwide. Decimal odds (e.g. 2.50) are popular in Europe and Australia — they show the total payout per unit staked. Fractional odds (e.g. 6/4) are traditional in the UK and Ireland — they show net profit relative to stake. American odds (e.g. +150 or -200) are standard in the US — positive numbers show profit on a $100 bet, negative numbers show how much you need to stake to win $100.
How do I convert between odds formats?
Use our Betting Odds Calculator for instant conversions. The formulas are: Decimal = Fractional + 1; for positive American odds, Decimal = (American / 100) + 1; for negative American odds, Decimal = (100 / |American|) + 1. Our calculator handles all conversions automatically in both directions.
What is implied probability?
Implied probability is the likelihood of an outcome as suggested by the odds. For example, decimal odds of 2.00 imply a 50% chance (1 / 2.00 = 0.50). Bookmakers build a margin into their odds, so the implied probabilities for all outcomes in a market will add up to more than 100%. The amount over 100% represents the bookmaker’s edge.
What is a bookmaker margin (overround)?
The bookmaker margin, also called overround or vig, is the built-in profit the bookmaker earns regardless of the outcome. If two outcomes in a market have implied probabilities of 52.4% each, the total is 104.8% — the 4.8% over 100% is the margin. Lower margins mean better value for bettors. Our No-Vig Calculator strips out this margin to show the true fair odds.
How do I remove the vig from odds?
To remove the vig (bookmaker margin), divide each outcome’s implied probability by the total of all implied probabilities, then convert back to odds. For example, if a two-outcome market has implied probabilities of 54.5% and 50.5% (total 105%), the true probabilities are 51.9% and 48.1%. Our No-Vig Calculator does this automatically for markets with any number of outcomes.
Why do odds matter for betting strategy?
Understanding odds is fundamental to profitable betting. Odds determine your potential return, the implied probability lets you compare the bookmaker’s assessment to your own, and finding discrepancies — where you believe the true probability is higher than what the odds suggest — is the basis of value betting. Without understanding odds, you cannot evaluate whether a bet offers good value.