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A bettor's calculations, done right
Eight calculators Babeth uses all the time. Your amounts stay in your browser.
Start here: check any odds
Boosted odds? Type the boosted price. A free bet to place? Free bet converter →
Check any odds: true chance, fair odds and edge →
All eight tools
Check your odds
A boosted price, a tip seen on social media, a slip someone sent you: pick the match, type the odds, and Babeth tells you the real chance of winning and whether the price is worth it. Free, no account, on matches in the next 4 days.
Open the tool →Free bet converter
A free bet or a money-back bet at your bookmaker: Babeth finds the odds that get the most out of it, from the true chance of every outcome. Free, no account.
Open the tool →Stake calculator (Kelly)
How much to stake for a given chance and odds? The Kelly formula maximizes bankroll growth; we take only a fraction to smooth drawdowns, never more than 5 % per bet.
Open the tool →Arbitrage (surebet) calculator
Two or three odds, at different bookmakers, covering every outcome of a match: if the sum of the inverses is below 1, you win whatever happens.
Open the tool →Odds ↔ probability converter
Odds are just a probability written differently. Switch between formats and see the implied chance (margin included).
Open the tool →Bookmaker margin and fair probabilities
Enter every odds of a market (the three of a 1X2, the two of a total): the implied probabilities add up to more than 100 %, the excess is the margin. Remove it and you get fair probabilities.
Open the tool →Parlay calculator
Total odds, probability and edge of a parlay. A parlay only has value if every leg has: a single leg without edge spoils everything.
Open the tool →Bankroll simulator
1,000 simulated seasons with fractional Kelly stakes (5 % cap) on the edge you enter: what your bankroll probably becomes, and the worst case to expect.
Open the tool →Sports betting glossary: the 30 terms you need to know
Value bet, closing line, margin, Kelly, surebet, sharp, bankroll, CLV… Short, exact definitions of the terms bettors meet, with links to the guides and tools.
Glossary →Babeth runs these calculations on thousands of markets every 60 seconds, with the true probability of every bet.
Try free for 14 days