Betting Tools
Calculators and converters built for serious sports bettors. Free, no sign-up required.
Line Shopping Calculator
See exactly how much money you leave on the table by not shopping for the best odds. Even a few cents of difference on every bet adds up to hundreds of dollars over a season.
Line Shopping Calculator
e.g. what we find
e.g. standard vig
Based on American odds · assumes same win rate across both lines
American ↔ European Odds Converter
Convert between American (moneyline), decimal (European), and fractional odds instantly. Edit either field and the other updates in real time.
Odds Converter
Edit either field — both update in real time
Implied Probability Calculator
Convert any American odds into the implied win probability — what the sportsbook thinks your chances are. Enter your own estimate to see whether there's genuine value in the bet.
Implied Probability Calculator
e.g. -110, +150
Optional — calculates edge
What the book thinks your odds of winning are
What the odds should be without the book's cut
Enter your own win estimate to see if there's value
Kelly Criterion Bet Sizer
Calculate the mathematically optimal bet size based on your edge and bankroll. Full, half, and quarter Kelly outputs — with an overbetting warning when the stake gets aggressive.
Kelly Criterion Bet Sizer
Your total betting bankroll
Your estimated chance of winning
The odds you're getting on the bet
Kelly maximises long-run growth · assumes accurate probability estimates