Fourteen free calculators covering the math sharp bettors actually use: odds conversion, expected value, closing line value, Kelly sizing, no-vig fair odds, hold and vig, arbitrage and hedging, round robin parlays, half-point shopping, bonus-bet conversion, spread ↔ ML conversion, Poisson score distributions, and parlay payouts. No signup, no marketing — just the math.
Convert between American, Decimal, Fractional, and Implied Probability instantly. The first step in any disciplined bet evaluation.
EV · Expected ValueEnter stake, win probability, and American odds; get EV in dollars, EV percent, edge over the market, and the breakeven win rate.
CLV · Edge MeasurementEnter your taken price and the closing line; get CLV in cents, implied-probability delta, and a verdict on whether you beat the close.
Kelly · Bet SizingEnter bankroll, win probability, and odds; get the bankroll-optimal bet size at full, half, or quarter Kelly — with a sanity cap built in.
No-Vig · Fair OddsEnter both sides of a two-way market; get the de-vigged fair odds for each side and the sportsbook's hold. Essential for CLV math.
Hold · Sportsbook MarginCalculate the sportsbook's margin on any two-way market. Sharp markets hold under 3%; player props hold 8–15%.
Vig · Effective TaxSee the vig in cents per $100 wagered — the bettor-side framing of the book's juice. Pair with No-Vig for full picture.
Arbitrage / HedgeSplit a stake across two opposing books for guaranteed-profit arbitrage, or size a hedge against an existing bet to lock in a fixed return.
Round Robin · Parlay CombosAdd any number of legs; get every round-robin size with combinations, total stake, and max payout. Useful for partial-loss-protected parlays.
Half Point · NFL Key NumbersCompare current and alternate spread odds; get the implied cost of the half-point and a flag when the move crosses an NFL key number (3, 7, 10, 14).
Bonus Bet · Free Bet ValueCompute the cash-equivalent expected value of any sportsbook free bet. Pick the right odds range to maximize conversion.
Point Spread ↔ MoneylineConvert any point spread to its equivalent moneyline using per-sport margin distributions. Flags push probability at NFL key numbers (3, 7, 10, 14).
Poisson · Score DistributionEnter expected goals/runs per team; get win/draw/loss probabilities, over/under fair lines, and most likely scorelines. Built for soccer, hockey, and MLB.
Parlay · Combined OddsAdd any number of legs; get combined American odds, payout, implied probability, and the effective parlay vig — the metric that explains why parlays rarely pay sharps.
The fourteen calculators above represent the full sharp-bettor math toolkit. Odds Converter handles format translation. EV measures the value of a single bet. CLV measures whether your picks beat the closing line over time. Kelly tells you how much to bet given a known edge. No-Vig, Hold, and Vig collectively expose the sportsbook's juice from three angles. Arbitrage and hedge sizing locks in profits across opposing markets. Round robin and parlay math explain combination-bet payouts and compounded vig. Half-point and bonus-bet calculators handle edge-case math sharps use to squeeze a few extra percent out of mature markets. Point Spread converts between spread and moneyline using per-sport margin distributions. Poisson models score distributions for soccer, hockey, and MLB.
Each tool runs entirely in your browser. No data leaves your device, no account is required, and the math is open for inspection in the page source. Deeper writeups on each topic are linked on the individual tool pages and in the Insights archive.