Betting Calculators
The same maths our confidence engine runs on, free and without an account. Everything here happens in your browser -- nothing you type is sent anywhere.
Building several parlays from one slate? The parlay builder spreads your legs so one game can't sink every ticket.
No-Vig (Fair Odds) Calculator
Strips the bookmaker's margin out of a two-way market to leave the fair price. This is the number to compare every other book against.
Expected Value Calculator
What a bet is worth per dollar staked, given your own estimate of how often it wins. Positive is the whole game.
Kelly Stake Calculator
How much to risk. Quarter Kelly is the headline number on purpose: full Kelly is only optimal if your probability is exactly right, and it punishes you hard when it isn't.
Closing Line Value Calculator
How far the market moved toward your side after you bet. Over a large sample this predicts long-run profit better than your win rate does -- the closing line is the sharpest price the market makes, and beating it repeatedly is hard to do by luck.
Hedge Calculator
The stake on the other side that pays you the same whichever way it lands.
Parlay Calculator
Payout and true odds for a multi-leg bet. Assumes the legs are independent -- correlated legs are worth more than this shows, which is exactly why books restrict them.
Odds Converter
American odds to decimal, fractional and the probability the price implies.