Sports betting
Sports betting: odds, markets and tools
Every bet comes down to a price. Learn to read it, see the margin hidden inside it, and work out what it pays before you bet. Guides to the main markets in each sport, and free calculators that run in your browser with no sign up.
Betting guides by sport
- Football betting1X2, double chance, Asian handicap, goals and BTTS.
- Basketball bettingSpreads, totals, moneylines and player props, NBA to college.
- Tennis bettingMatch winner, set betting, handicaps and retirement rules.
- UFC bettingMoneyline, method of victory, rounds and goes the distance.
- Volleyball bettingSet betting, set and points handicaps, total points, indoor and beach.
How to read odds
US sportsbooks quote American odds. A plus number is the profit on a $100 stake: +150 wins $150. A minus number is what you stake to win $100: -150 means $150 to win $100. The rest of the world mostly uses decimal odds (2.50 returns $2.50 for each $1 staked, stake included) or fractional odds (3/2). They are three ways of writing the same price; the odds converter switches between them.
What a price says about the chance of winning
Divide 1 by the decimal odds and you have the implied probability: -150 implies 60%, +150 implies 40%. It is also the break even rate: a bet at that price has to win that often just to come out even over time. Check any price with the implied probability calculator.
The margin inside every market
Add up the implied probabilities of every outcome and you get more than 100%. On a typical spread at -110 on both sides, that is 104.76%. The extra is the sportsbook's margin, also called the vig or juice; on balanced action it keeps 4.55% of the money wagered. The no vig calculator removes it to show the fair price.
Payouts and parlays
A bet's payout is the stake times the decimal odds: $10 at -110 pays $19.09. A parlay multiplies the odds of every leg, and with them the margins: two -110 legs pay +264, while two fair coin flips would pay +300. See it for any bet with the betting calculator and the parlay calculator.
Free betting calculators
All calculators- Odds converterAmerican, decimal, fractional, Hong Kong, Indonesian and Malay odds, converted as you type.
- Betting payout calculatorProfit, total payout and implied probability for any stake and price.
- Parlay calculatorCombine 2 to 15 legs: parlay odds, payout and the chance every leg wins.
- Implied probability calculatorThe win chance a price implies, its break even rate, and odds from a probability.
- No vig calculatorStrip the bookmaker's margin from a 2-way or 3-way market to get fair odds.
- Double chance & draw no bet calculatorFair 1X, X2, 12 and draw no bet prices from football 1X2 odds.
- Point spread & total calculatorImplied team scores from a spread and total, plus the vig on each line.
- Tennis set betting calculatorSet score chances and fair set betting odds from match odds, best of 3 or 5.
- UFC method of victory calculatorFair KO, submission and decision odds, and the chance the fight goes the distance.
- Round robin calculatorEvery parlay in a round robin by 2s, 3s or more: total stake, best case and any result.
- Bonus bet calculatorWhat a free or bonus bet is worth, and how much cash a hedge locks in.
- Expected value (EV) calculatorExpected profit, edge and break even rate from a price and your own win estimate.
- Kelly criterion calculatorFull, half and quarter Kelly stakes from your bankroll, the price and your estimate.
- Hedge calculatorHow much to bet on the other side to lock in profit or cut a loss, with both outcomes.
- Arbitrage calculatorCheck whether prices at two or three sportsbooks leave an arbitrage, and how to split stakes.
- Bankroll calculatorUnit size from your bankroll and risk level, stakes in units, and what a losing run does.
- Closing line value (CLV) calculatorHow the price you took compares with the closing line, with or without the vig.
- Volleyball set betting calculatorSet score chances (3-0 to 2-3), total sets and set handicaps from match odds, indoor or beach.
- Volleyball points calculatorFair over/under total points and points handicap prices from match odds.
Where sports betting is legal
Sports betting is legal in many US states, but not all. Each state that allows it licenses its own sportsbooks, decides which sports and markets are allowed and sets the minimum age, which is 21 in most of them and 18 in a few. Online betting only works while you are physically inside a state where it is legal. Many states also have retail sportsbooks inside casinos; several of the Atlantic City casinos and Pennsylvania casinos in this guide have one.
Common questions
What does +150 mean in sports betting?
A $100 bet wins $150 in profit, $250 back in total. Plus odds mark the underdog; minus odds like -150 mark the favorite and show what you stake to win $100.
What is the vig?
The sportsbook's margin. With -110 on both sides of a line, each side implies 52.4%, 104.8% in total; on balanced action the book keeps about 4.5% of the money wagered.
Is sports betting legal in the US?
In many states but not all. Each state that allows it licenses its own sportsbooks and sets its own rules; the minimum age is 21 in most of them and 18 in a few, and to bet online you must be physically inside a state where it is legal.
Do these calculators tell me who will win?
No. They show what prices imply and what a bet pays. Any probability you enter yourself is an assumption, not a forecast.
Why do parlays pay less than they seem to?
Each leg carries the sportsbook's margin and a parlay multiplies them. Two -110 legs pay +264; two fair coin flips would pay +300.
Betting involves risk. Calculators show what prices imply, not what will happen. Set a budget before you start, never chase losses, and if betting stops being fun, call or text 1-800-GAMBLER for free, confidential help.
More help: playing responsibly and where to get help.