Free Betting Tools
Parlay math, hedge calculations, expected value, breakeven win rates, and a prediction market converter you won't find anywhere else. Built by bettors, free for everyone.
No account. No paywall. No catch. 21+
Pick Your Tool
Five Calculators, Zero Cost
Prediction Market Converter
Turn a Kalshi, Polymarket, or Robinhood contract price into the American odds you actually get after trading fees — then see whether it beats your sportsbook.
Open converter →Parlay Calculator
Add any number of legs, see your true payout, total odds, and the real probability of hitting it.
Open calculator →Hedge Calculator
Work out the exact hedge stake to lock in equal profit either way — or cut a loss on a bet that's gone wrong.
Open calculator →Expected Value Calculator
Compare your read to the market price and find out whether a bet is genuinely +EV. Includes a no-vig fair-odds tool.
Open calculator →Breakeven Calculator
Find the win rate you need at any price just to stay level. The number most bettors have never actually checked.
Open calculator →Why we give these away
Most betting calculators online are wrappers around an affiliate link. You punch in numbers, and the page's real job is getting you to click a sportsbook banner.
Ours aren't. There's no signup, no email capture in front of the tool, and no sportsbook offer on this page. We build them because we use them, and because a bettor who understands the math is a better long-term reader than one who doesn't.
What each one is actually for
The parlay calculator tells you what a multi-leg bet truly pays and — more usefully — what your real chance of hitting it is. Most people are surprised by the second number.
The hedge calculator matters when a bet has moved in your favor and you're deciding whether to lock something in. It gives you the exact stake for equal profit either way, plus a custom mode if you'd rather keep some upside.
The EV calculator is where the actual work happens. If you can estimate a true probability better than the market can, it tells you whether the number in front of you is worth taking. The built-in no-vig tool strips the book's margin out of a two-way market so you're comparing against a fair price rather than a padded one.
The breakeven calculator answers a question most bettors never ask: at this price, how often do I need to be right just to not lose money? At standard -110, the answer is 52.38%. Knowing that number changes how you look at a bet.
The prediction market converter is the one nobody else has built. Contract prices on Kalshi and Polymarket look like clean probabilities, but you pay a trading fee on top of the price — so a 55¢ contract isn't really -122. This prices the fee in, shows you the odds you're truly getting, and tells you the maximum contract price at which the exchange still beats the sportsbook line.
A note on how to use them
These tools do arithmetic. They don't tell you who's going to win, and no calculator can. What they do is stop you from taking a price that was never good enough in the first place — which, over a season, is worth more than most people expect.
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