Betting Calculators That Just Work

Fast, free tools for odds, accumulators, system bets, Kelly staking and value — no sign-up, no clutter.

System Bet Tools

Alphabet Calculator

Work out the returns on an Alphabet: twenty-six bets across six picks, made of two Patents, a Yankee and a six-fold, in dollars.

Canadian (Super Yankee) Calculator

Work out the returns on a Canadian, also called a Super Yankee: twenty-six bets across five moneyline picks.

Double Stakes About (DSA) Calculator

Work out the return on a Double Stakes About - two any-to-come bets that reinvest double the stake on the other pick - from American odds, in dollars.

Flag Calculator

Work out the returns on a Flag: a Yankee plus six up-and-down pairs, twenty-three bets on four moneyline picks.

Goliath Calculator

Work out the returns on a Goliath: two hundred and forty-seven bets across eight moneyline picks.

Goliath Flag Calculator

Work out the returns on a Goliath Flag: a Goliath plus twenty-eight up-and-down pairs, three hundred and three bets.

Heinz Calculator

Work out the returns on a Heinz: fifty-seven bets across six moneyline picks, with no singles.

Heinz Flag Calculator

Work out the returns on a Heinz Flag: a Heinz plus fifteen up-and-down pairs, eighty-seven bets on six moneyline picks.

Lucky 15 Calculator

Work out the returns on a Lucky 15: fifteen bets across four moneyline picks, singles included.

Lucky 31 Calculator

Work out the returns on a Lucky 31: thirty-one bets across five moneyline picks, singles included.

Lucky 63 Calculator

Work out the returns on a Lucky 63: sixty-three bets across six moneyline picks, singles included.

Patent Calculator

Work out the returns on a Patent: seven bets across three moneyline picks, singles included.

Round Robin Calculator

Work out the returns on a Round Robin: a Trixie plus three up-and-down pairs, ten bets on three moneyline picks.

Single Stakes About (SSA) Calculator

Work out the return on a Single Stakes About - two any-to-come bets that reinvest one pick's winnings on the other - from American odds, in dollars.

Super Flag Calculator

Work out the returns on a Super Flag: a Canadian plus ten up-and-down pairs, forty-six bets on five moneyline picks.

Super Heinz Calculator

Work out the returns on a Super Heinz: one hundred and twenty bets across seven moneyline picks.

Super Heinz Flag Calculator

Work out the returns on a Super Heinz Flag: a Super Heinz plus twenty-one up-and-down pairs, one hundred and sixty-two bets.

Trixie Calculator

Work out the returns on a Trixie: four bets across three moneyline picks, with no singles.

Union Jack Patent Calculator

Work out the returns on a Union Jack Patent: nine picks in a 3x3 grid with each of the eight lines played as a Patent.

Union Jack Round Robin Calculator

Work out the returns on a Union Jack Round Robin: nine picks in a 3x3 grid with each line played as a Round Robin.

Union Jack Trebles Calculator

Work out the returns on a Union Jack Trebles: nine moneyline picks in a 3x3 grid played as eight three-pick parlays.

Union Jack Trixie Calculator

Work out the returns on a Union Jack Trixie: nine picks in a 3x3 grid with each of the eight lines played as a Trixie.

Yankee Calculator

Work out the returns on a Yankee: eleven bets across four moneyline picks, with no singles.

Value & Strategy Tools

Arbitrage Calculator

Split a stake across two sportsbooks on opposite sides of a game to lock in a guaranteed profit whichever way it lands, in dollars.

Betting ROI Calculator

Work out your betting return on investment - profit as a percentage of everything you staked - to measure how well your bankroll is performing, in dollars.

Bookmaker Margin Calculator

Compare how much margin different sportsbooks build into the same market, from their American odds, to find the sharpest prices.

Buying Half Points Calculator

See what buying a half point costs - how much profit you give up when you move a spread or total in your favor by moving the price, in dollars.

Closing Line Value (CLV) Calculator

Measure how much you beat the closing line by, comparing the American odds you took with the price at kickoff, as a percentage.

Dutching Calculator

Split a stake across two or more selections in one market so every winner returns the same amount, worked from American odds in dollars.

Expected Value (EV) Calculator

Work out the expected value of a bet from your true win probability and the American odds, to see if a price is a long-run winner.

Hold Percentage Calculator

Measure a sportsbook's hold - the margin baked into a market - by adding the implied probabilities of every outcome from their American odds.

Kelly Criterion Calculator

Find the mathematically optimal stake for a bet from your edge and the American odds, sized as a percentage of your bankroll.

Strike Rate Calculator

Find the break-even strike rate any price demands - the share of bets you must win at given American odds just to stay even, as a percentage.

Surebet Calculator

Check whether two odds form a surebet and get the exact stake on each side to guarantee the same profit whichever result lands, in dollars.

Win-Loss Record Calculator

Turn a win-loss record into a win percentage and a net profit in units, and see the break-even rate you need at -110, in dollars.

Winning & Losing Streak Calculator

Work out the probability of a run of wins or losses from your win rate, so you can size a bankroll that survives the cold spells, in dollars.

Betting Glossary

Action

Any wager on a sporting event; also confirms a bet is live and valid.

Against the Spread (ATS)

A team's record measured against the point spread instead of the straight-up result.

Arbitrage Betting

Backing every outcome across different books to lock in a guaranteed profit no matter the result.

Asian Handicap

Soccer spread betting that removes the draw by applying fractional or whole-number handicaps to one or both teams.

Bad Beat

A bet that looks certain to win but loses on a last-minute or highly improbable event.

Bankroll

The pool of money a bettor reserves only for wagering, walled off from everyday personal finances.

Betting Handle

The total money wagered on an event or over a set period.

Betting Limits

The minimum and maximum a bookmaker will take on a single bet.

Bonus Bet (Free Bet)

A promo bet where the book funds the stake; win and you keep the profit but usually not the original stake.

Buying Points

Paying worse odds to get a better spread or total, often to cross key football numbers like 3 and 7.

Cash Out

Settle an open bet before the event ends to lock a profit or cut a loss.

Chalk

Slang for the favorite; 'betting the chalk' means backing the side expected to win.

Closing Line Value (CLV)

The gap between your bet's odds and the final closing odds, used to gauge betting skill.

Cover

A team covers when it beats the point spread, not just the final result.

Double Chance

A bet covering two of three soccer outcomes (home/draw, away/draw, home/away) for lower risk and lower odds.

Edge

Your advantage over the book: the true probability of an outcome is higher than the probability baked into the offered odds.

Even Money

A bet where profit equals the stake: decimal 2.00, fractional 1/1, American +100.

Expected Value (EV)

The average amount a bettor wins or loses per bet over the long run.

Fade the Public (Contrarian Betting)

Betting against the side most recreational bettors back, on the theory that public sentiment creates value on the other side.

Favorite vs Underdog

The favorite is expected to win (lower odds/shorter price); the underdog is expected to lose (higher odds/longer price).

Futures Bet

A wager on an outcome decided later, like a season title or tournament winner.

Hedging

Betting the opposite side of an existing wager to lock in profit or cut potential loss whatever the result.

Hook

The half-point in a spread (e.g., -3.5 instead of -3) that removes any chance of a push.

Implied Probability

The chance of an outcome as implied by the odds, with the bookmaker's margin included.

Juice / Vigorish (Vig)

The bookmaker's commission on each bet, built into the odds.

Kelly Criterion

A formula that sets the optimal stake size from your perceived edge and bankroll.

Key Numbers

The most frequent winning margins in a sport, which make some spreads matter far more than others.

Line Movement

A shift in the odds or spread after the opener, driven by betting action, injuries, weather, or news.

Line Shopping

Comparing odds across multiple books to lock in the best available price for a bet.

Live Betting (In-Play)

Betting on an event while it's in progress, with odds updating in real time.

Matched Betting

Combining sportsbook promos like bonus bets and odds boosts with opposing wagers to lock in guaranteed profit at minimal risk.

Middling

Betting both sides of a game at different spreads to win both if the final margin lands in the gap between the two numbers.

Moneyline

A bet on who wins outright, with no point spread involved.

No Action

A cancelled bet with the stake returned, usually from a postponed event, scratched player, or voided conditions.

Odds Boost

A promo where the book temporarily raises the odds on a specific market, handing bettors enhanced potential returns.

Odds Formats

The three standard notations for displaying odds: Decimal, Fractional, and American (Moneyline).

Oddsmaker / Bookmaker

The person or company that sets lines and odds, manages risk, and takes wagers on sporting events.

Off the Board

A game or market the sportsbook has temporarily pulled from betting, usually over uncertainty like injuries or weather.

Opening Line / Closing Line

The opening line is the first odds released; the closing line is the final odds before the event starts.

Over/Under (Totals)

A bet on whether the combined score of a game finishes over or under a set number.

Parlay (Accumulator)

One bet tying together two or more picks. Every leg has to win or the whole ticket loses.

Pick'em

A game with no favorite. The spread is zero, so you just pick the winner.

Player Prop vs Game Prop

Player props bet on one athlete's stats; game props bet on team or match events like first team to score.

Point Spread

A handicap that levels the field between favorite and underdog.

Profit Boost

A promo that adds a percentage to a winning bet's profit (e.g. +50%), unlike an odds boost which raises the odds themselves.

Prop Bet (Proposition Bet)

A wager on a specific in-game occurrence that need not affect the final result.

Public Betting Percentage

The share of total bets on each side of a market, showing where most recreational bettors landed.

Push

A tie against the spread or total; no one wins and the stake is returned.

Qualifying Bet

A bet you must place to unlock a promotion, usually with minimum odds and stake rules.

Reload Bonus

A deposit bonus for existing customers on later deposits, unlike a first-time sign-up offer.

Reverse Line Movement

The line moves opposite to where most public bets sit, flagging sharp (pro) money on the other side.

Risk-Free Bet

A promo that refunds your stake — usually as a bonus bet — if your first bet loses.

ROI (Return on Investment)

Profit or loss as a percentage of total money wagered.

Round Robin

A combo bet that builds multiple parlays from a group of selections, covering different subset combinations.

Run Line / Puck Line

A sport-specific spread — a fixed 1.5-run spread in baseball (MLB) and a fixed 1.5-goal spread in hockey (NHL).

Same-Game Parlay

A parlay whose legs all come from one game or event.

Sharp vs Square

Sharps are pros who bet with an edge; squares are recreational bettors who follow public sentiment.

Site Credit

Non-withdrawable account funds you bet with; winnings are usually withdrawable.

Stale Line

Odds not yet updated for new info (injuries, lineup changes), leaving value for alert bettors.

Steam Move

A sudden, sharp line move driven by heavy action from pro bettors or syndicates.

Straight Bet

A single wager on one outcome -- moneyline, point spread, or total -- not a parlay or combination ticket.

Teaser

A parlay that lets you shift the point spread or total in your favor in exchange for reduced odds.

Tout

A person or service that sells betting picks, often with exaggerated claims about win rates.

Units

A standardized bet-size measure tied to bankroll, used to track and compare results regardless of dollar amounts.

Variance (in Betting)

The natural swing in results that happens even when you are placing positive expected value bets.

Wagering Requirements (Rollover)

How many times you must wager a bonus or deposit before any winnings can be withdrawn.