18 Free Sports Betting Calculators — No Signup Required
VigMath is the most comprehensive free sports betting calculator toolkit on the internet. Built for sharp bettors, casual players, arbitrage hunters, and everyone in between. Every tool runs instantly in your browser with zero signups, zero ads, and zero tracking. Whether you're betting NFL, NBA, MLB, NHL, college football, soccer, UFC, tennis, or any other sport — VigMath has the math covered.
Odds Converter — American, Decimal, Fractional & Implied Probability
Instantly convert between American odds (moneyline), decimal odds, fractional odds, and implied probability. Enter any format and all others auto-fill. Includes wager amount and payout calculation. Whether you're comparing lines across DraftKings, FanDuel, BetMGM, Caesars, ESPN BET, Fanatics, bet365, or offshore books like Pinnacle, Bovada, and BetOnline — our converter gives you the full picture. Supports positive and negative American odds, decimal odds from any international market, and UK fractional odds.
Parlay Calculator — Multi-Leg Parlay Payout & Odds
Calculate the combined payout, total odds, and implied probability of any multi-leg parlay. Add unlimited legs, adjust your wager, and instantly see your potential payout and the true likelihood of hitting. Works for standard parlays, same-game parlays (SGPs), teasers, and round robins. See your combined American odds, decimal odds, and the true implied probability so you understand exactly what you're up against. Perfect for NFL Sunday slates, NBA player props, MLB run lines, and any multi-leg bet.
Kelly Criterion Calculator — Optimal Bet Sizing
The Kelly Criterion is the mathematically optimal formula for bet sizing based on your edge and bankroll. Developed by John Kelly at Bell Labs, it maximizes long-term bankroll growth while managing risk. Our calculator shows full Kelly, half Kelly (recommended by most professional sports bettors), and quarter Kelly (conservative) bet sizes. If you're serious about bankroll management, proper bet sizing with Kelly is essential. Also shows your edge over the book and expected value per bet.
Hedge Calculator — Lock In Guaranteed Profit
Lock in guaranteed profit on futures, parlays, and live bets. Enter your original wager, original odds, and the current hedge odds to calculate the exact bet amount needed for equal profit on both sides. Perfect for Super Bowl futures, March Madness brackets, NBA Finals bets, World Series futures, playoff scenarios, and any situation where you want to secure your winnings. Shows profit for both outcomes, total invested, and ROI.
Expected Value (EV) Calculator — Find +EV Bets
Determine whether a bet is +EV (positive expected value) or -EV based on your estimated true probability versus the sportsbook's odds. Sharp bettors and professional handicappers know that consistently finding +EV spots is the only path to long-term profit in sports betting. Our calculator shows your EV per bet, EV per dollar wagered, your edge over the book, and projected results over 100 bets. The foundation of profitable sports betting is identifying and exploiting +EV opportunities.
Hold / Vig Calculator — Sportsbook Margin Exposed
See exactly how much the sportsbook is charging you in vig (vigorish), juice, or hold. Enter both sides of any 2-way line and our calculator reveals the hold percentage, the true no-vig probabilities, and the fair odds you'd get at a zero-margin book like a betting exchange. Compare hold across DraftKings, FanDuel, BetMGM, Caesars, Pinnacle, and more to find the best value. A standard -110/-110 line carries about 4.76% hold — every point of hold you save goes straight to your bottom line.
Arbitrage Calculator — Guaranteed Profit Both Sides
Find guaranteed profit opportunities by betting both sides of a market across different sportsbooks. When the combined implied probability across two books is less than 100%, an arbitrage (arb) opportunity exists. Our calculator tells you the exact dollar amount to bet on each side for risk-free profit, the arbitrage percentage, ROI, and payouts for each outcome. Arb betting is legal and commonly used by sharp bettors who shop lines across multiple sportsbooks including DraftKings, FanDuel, BetMGM, Caesars, PointsBet, and Pinnacle.
Free Bet Converter — Turn Bonus Bets Into Cash
Every major sportsbook offers free bets and bonus bets as promotions — but most bettors waste them on longshots. Our free bet converter calculates the optimal hedge to turn your free bet into guaranteed cash. Enter your free bet amount, the odds you're placing it at, and the hedge odds at another book. The calculator shows your guaranteed cash extraction and conversion rate. Use odds of +300 or longer on the free bet for the best conversion rates (typically 60-80% of face value). Works for DraftKings bonus bets, FanDuel bonus bets, BetMGM free bets, Caesars bonus bets, and any sportsbook promotion.
Round Robin Calculator — Every Parlay Combination
Enter 3 or more selections and calculate every possible parlay combination — 2-leg parlays, 3-leg parlays, and beyond. See the total cost, individual payouts, number of bets, and max profit if all legs hit. Round robins give you more ways to profit even if not every leg hits, making them a popular alternative to straight parlays. Choose specific parlay sizes or calculate all sizes at once. Perfect for NFL Sundays when you like multiple games but don't want everything riding on one massive parlay.
Closing Line Value (CLV) Tracker — The #1 Profitability Metric
Closing line value is the single most predictive metric for long-term sports betting profitability. If you consistently get better odds than where the line closes at game time, you are a winning bettor — period. Our CLV tracker lets you compare the odds you locked in versus the closing line and shows your exact CLV percentage, implied probabilities, and whether you're beating the market. Used by professional bettors, betting syndicates, and anyone serious about tracking their edge. Track your CLV over time to validate your handicapping process.
Dutching Calculator — Equal Profit Across Multiple Selections
Dutching allows you to bet on multiple selections in the same event and guarantee equal profit regardless of which one wins. Enter the odds for each selection and your total stake — the calculator computes the optimal bet amount for each selection. Commonly used in horse racing, golf tournaments, UFC fights, NASCAR, and any event with multiple possible winners. If the combined implied probability of your selections is under 100%, dutching produces a guaranteed profit similar to arbitrage.
3-Way Hold Calculator — Soccer & Three-Outcome Markets
Our standard hold calculator handles 2-way markets. But soccer (football), hockey regulation, and other sports often have 3 possible outcomes: home win, draw, and away win. The 3-way hold calculator shows you the sportsbook's margin on these markets, the true no-vig probability for each outcome, and the fair odds. Three-way markets typically carry higher hold than 2-way markets, making it even more important to shop for the best lines. Works for Premier League, La Liga, Serie A, Bundesliga, Champions League, MLS, and any 3-way market.
Bankroll Simulator — Monte Carlo Simulation
Visualize your betting future with our Monte Carlo bankroll simulator. Enter your starting bankroll, bet size, win probability, odds, and number of bets — then run hundreds of simulated betting paths. See your expected final bankroll, median outcome, best and worst case scenarios (5th and 95th percentiles), risk of ruin (going broke), and percentage of profitable runs. Includes a histogram chart showing the full distribution of outcomes. Essential for understanding variance in sports betting and validating your bankroll management strategy.
Promo / Bonus Value Calculator — Sportsbook Promotions
Sportsbooks spend billions on promotions to acquire new customers. Our calculator tells you the true dollar value of three common promo types: deposit matches (accounting for rollover requirements), risk-free/second chance bets (including free bet conversion value), and bonus bets/free bets (with optimal hedging). Stop guessing what a "Bet $5 Get $200 in Bonus Bets" offer is actually worth. Whether it's a DraftKings deposit match, FanDuel bonus bet, BetMGM risk-free bet, or Caesars first bet, our calculator gives you the real number.
Bet Tracker — Log Bets & Track Your Record
Track every bet you place with VigMath's built-in bet tracker. Log the date, event, odds, stake, and result for each bet. The tracker automatically calculates your running stats: total bets, win-loss record, total profit/loss, ROI, average odds, and units won. All data is stored locally in your browser using localStorage — we never see your betting history. Export to CSV anytime. Whether you're tracking NFL season-long results, NBA player props, or MLB run lines, knowing your actual numbers is the first step to becoming a sharper bettor.
Break-Even Calculator — Win Percentage Needed at Any Odds
One of the most important concepts in sports betting is understanding the win rate you need to be profitable at given odds. At standard -110 juice, you need to win 52.38% of your bets just to break even. At +150, you only need 40%. VigMath's break-even calculator instantly shows the required win percentage for any American odds, plus a table showing your expected profit per $100 at various win rates above and below the break-even point. High SEO value for the keyword "break even calculator betting."
Poisson Distribution Calculator — Soccer Score Probabilities
The Poisson distribution is the gold standard statistical model for predicting soccer scores. Enter the expected goals (xG) for each team and VigMath generates a complete score probability matrix from 0-0 through 5-5, showing the probability of every possible scoreline. The calculator also derives over/under probabilities for totals from 0.5 through 5.5, and BTTS (both teams to score) probability. Used by professional soccer bettors, betting models, and analytics teams worldwide. Works for Premier League, La Liga, Serie A, Bundesliga, Champions League, MLS, and any soccer match where you have expected goals data.
Odds Comparison Table — Find the Best Line
Line shopping is the single easiest way to increase your sports betting profits. VigMath's odds comparison tool lets you manually enter odds from up to 6 sportsbooks for any two-way market. The tool highlights the best odds in green, calculates the hold (vig) for each book, and shows the no-vig fair odds derived from the best available line. Compare odds across DraftKings, FanDuel, BetMGM, Caesars, ESPN BET, Pinnacle, and any other book to ensure you're always getting the best price.
Who is VigMath for?
VigMath is built for anyone who wants to bet smarter. Recreational bettors who want to understand their bets better. Sharp handicappers optimizing their edge and tracking CLV. Arbitrage bettors who shop lines across multiple books. Bonus hunters maximizing sportsbook promotions. Content creators and sports betting media who need quick, reliable calculations. Poker players crossing over to sports betting. Fantasy sports players looking to add sports betting tools to their arsenal. All 14 tools work on mobile and desktop with no app download required.
Sports Covered
VigMath's calculators work for every sport and every market. NFL football (spreads, totals, moneylines, player props, team props, futures). NBA basketball. MLB baseball. NHL hockey. College football (NCAAF) and college basketball (NCAAB). Soccer (EPL, La Liga, Serie A, Bundesliga, Champions League, MLS, World Cup). UFC and MMA. Tennis (ATP, WTA, Grand Slams). Golf (PGA Tour, LIV). NASCAR and Formula 1. Boxing. Cricket. Esports. If there are odds, VigMath can calculate it.
Why VigMath?
Unlike other betting calculator sites, VigMath is 100% free with no paywalls, no email capture, no ads, and no tracking. Every calculation runs client-side in your browser — we never see your data. We're built by bettors, for bettors. Bookmark VigMath and use it every time you place a bet. It's the sharpest free toolkit on the internet.