Betting Calculators

Every calculator here does one job and shows every step — no black box, no signup, free. Paste your numbers; the answer is computed live, with the math laid out underneath. Each one has a full lesson behind it in the Learn course.

No-Vig Calculator Expected Value (+EV) Calculator Kelly Criterion Calculator Arbitrage Calculator Closing Line Value Calculator Free Bet & Bonus Bet Calculator Parlay Calculator

Five of these chain together: de-vig a line to its fair probability, use that to spot an +EV price, size the bet with Kelly, lock a rare arbitrage when two books disagree, and grade every bet after the fact by its closing line value — the fastest honest measure of skill. Two more stand on their own: the free-bet converter tells you what a sportsbook’s bonus token is really worth, and the parlay calculator shows the combined odds, payout, and the compounded vig behind any parlay. The full derivations and worked examples live in the free Learn guides.