Free betting tools
Fast, free calculators — no signup required. Built on the same engine that powers Bankroll Guardian.
Parlay calculator
Enter each leg in American odds to get the combined price, payout and profit — plus a risk read: how often the parlay actually hits, the stacked vig you're paying, and which legs are the weak links.
Open tool →Odds converter & chart
Convert between American, decimal and fractional odds, see the implied win probability — plus a full betting odds chart of every common price.
Open tool →Bet calculator
Enter American odds and your stake to see the profit, total payout and implied win probability.
Open tool →Expected value (EV) calculator
Enter the odds and the win probability you believe to see whether a bet is positive expected value.
Open tool →No-vig & hold calculator
Enter both sides of a market to see the bookmaker’s hold and the fair, no-vig odds and probabilities.
Open tool →Closing Line Value (CLV) calculator
Compare the price you got to the closing line to see your CLV — the clearest sign of a long-term edge.
Open tool →Hedge calculator
Size a hedge bet on the opposite outcome so your profit is the same whichever way it lands.
Open tool →Arbitrage calculator
Enter both sides’ odds from different books to see if there’s an arb, and exactly how to split your stake for the same profit either way.
Open tool →Bankroll calculator
Enter your bankroll to get your unit size, compare 0.5%–10% staking plans side by side, and see how many consecutive losses each one survives before halving your bankroll.
Open tool →Kelly criterion calculator
Enter the odds, your estimated win probability and your bankroll to get the Kelly-optimal stake — full, half or quarter.
Open tool →Stop calculating by hand
Bankroll Guardian tracks every bet and shows your P&L, ROI, CLV and where you’re leaking — free to start.