Bet math, made plain.
Type any odds — see all three formats instantly.
Bet Calculator
Payout, profit, and implied probability for any single bet.
$100 at +150 → $250 payout
Parlay Calculator
Combine 2–15 legs. Combined payout and built-in hedge calculator.
3 legs at −110 → +596 (6.96×)
Moneyline Calculator
Profit, payout, and implied probability for any moneyline bet.
$50 at −200 → $25 profit
Point Spread Calculator
Standard −110 spread payouts and implied probability.
$110 at −110 → $100 profit
Over/Under Calculator
Totals juice payouts and implied probability for any over or under.
O 47.5 at −115 → 53.5% implied
NFL Parlay Calculator
Stack NFL spreads, moneylines, and totals with hedge math.
4-leg NFL parlay → +1228
Specialized & advanced
EV & Kelly
Expected value, EV%, and Kelly stake sizing.
+5.2% EV → 2.1% Kelly
Round Robin Parlay
Every smaller-parlay combination from your selections.
4 legs → 11 parlays
No-Vig
Strip the sportsbook's juice. See the fair line.
−110 / −110 → 50.0% fair
Arbitrage
2-way and 3-way risk-free splits across books.
+105 / −100 → 1.2% locked
Line Shopping
Compare 2–6 books, find the best line.
DK +105 wins over FD +100
Unit Size
Bet sizing from bankroll and unit %.
$5,000 × 1% → $50 unit
Risk of Ruin
Probability of going broke at your bet size.
55% win, 2u → 1.4% ruin
Losing Streak
Expected cold runs given your win rate.
55%, 500 bets → ~7 streak
Prediction markets (Kalshi & Polymarket)
Odds Converter
Contract price (cents) → implied %, American, decimal.
65¢ → 65% → −186
Kalshi Fee
Trading fee by contract price. Peaks near 50¢.
50¢ × 100 → ≈$1.76 fee
Kalshi Payout
Cost, max payout, profit, fee-adjusted breakeven.
100 at 65¢ → $33 if Yes
Kalshi Arbitrage
Cross-platform arb: Kalshi vs Polymarket vs books.
60¢ + 38¢ → 2% risk-free
Combo (Parlay)
Fair combo price from the legs, plus the markup on a quote.
4 × 60¢ → 13¢ fair
Learn the math behind the calculators
Plain-English explainers for the queries that get asked most: what does +150 mean, how to remove vig, what is Kelly staking, how much does a $10 parlay pay, reading Kalshi prices. Browse all 10 guides →
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