Free betting tools
The calculators we use ourselves. Everything runs in your browser, nothing is stored.
Bookmaker margin calculator
See how much the bookmaker keeps before kickoff, and the fair odds.
Closing line value calculator
Did you beat the closing price? Check one bet or paste your last bets.
Odds to probability and unit size
Turn odds into implied probability and your bankroll into a unit size.
Line shopping calculator
Compare up to 4 bookmakers and see what the better price is worth.
Tipster record checker
Is that record skill or noise? Check ROI, error and sample size.
Losing-run simulator
Simulate 2.000 seasons and see the losing runs a winning bettor faces.
Bankroll planner
A realistic 3-month range for your bankroll, not a single number.
Get the 7-day course
One short email a day on margin, CLV, stakes and variance. Free.
Get the free course18+ · Bet responsibly · See our record