Betting Calculators That Just Work
Fast, free tools for odds, accumulators, system bets, Kelly staking and value — no sign-up, no clutter.
Odds & Conversion Tools
Moneyline Tool
Convert American moneyline prices to decimal, fractional and implied probability.
Implied Probability Tool
Turn bookmaker odds into true probabilities for one or several outcomes.
No-Vig Tool
Strip the bookmaker margin to reveal fair odds and true no-vig probabilities.
Odds Conversion Tool
Instantly convert decimal, fractional and American odds and read the implied probability.
Point Spread Tool
Convert point spreads to moneylines and implied probabilities to see what a line means.
Quick Odds Tool
Type odds in any format and see every equivalent at once — decimal, fractional, American.
Single & Multiple Bet Tools
Accumulator Tool
Combine several selections and see how the multiplied odds build your potential return.
Double Bet Tool
Returns for a two-selection double — both legs must land for the bet to pay.
Parlay Tool
Combined odds and payouts for multi-leg parlays, the US staple of multiple betting.
Single Bet Tool
Enter stake and odds for instant returns and profit in decimal, fractional or American.
Treble Bet Tool
Returns for a three-selection treble — all three must win for a bigger payout.
System Bet Tools
Alphabet Bet Tool
Returns for the 26-bet Alphabet on 6 selections — two patents, a yankee and a six-fold.
Canadian Bet Tool
Returns for a Canadian (Super Yankee): 26 bets across 5 selections.
Double Stakes About Tool
Returns for a Double Stakes About (DSA) — a conditional any-to-come bet on two picks.
Flag Bet Tool
Returns for a 23-bet Flag on 4 selections: doubles, trebles, a four-fold and SSA pairs.
Goliath Bet Tool
Returns for a Goliath: 247 bets across 8 selections, from doubles up to an eight-fold.
Goliath Flag Tool
Returns for a 303-bet Goliath Flag on 8 selections, including SSA pairs.
Heinz Bet Tool
57 bets on 6 selections: 15 doubles, 20 trebles, 15 four-folds, 6 five-folds and a six-fold.
Heinz Flag Tool
Returns for an 87-bet Heinz Flag on 6 selections, including SSA pairs.
Lucky 15 Tool
15 bets on 4 selections: 4 singles, 6 doubles, 4 trebles, a four-fold — one winner pays.
Lucky 31 Tool
31 bets on 5 selections from singles to a five-fold — a single winner returns.
Lucky 63 Tool
63 bets on 6 selections — full coverage from singles up; one winner guarantees a return.
Patent Bet Tool
7 bets on 3 selections: 3 singles, 3 doubles and a treble — one winner returns.
Round Robin Tool
Build every parlay from 3-8 picks and see all 2-way and larger combinations.
Single Stakes About Tool
Returns for a Single Stakes About (SSA) — a conditional any-to-come bet on two picks.
Super Flag Tool
Returns for a 46-bet Super Flag on 5 selections, including SSA pairs.
Super Heinz Flag Tool
Returns for a 162-bet Super Heinz Flag on 7 selections, including SSA pairs.
Super Heinz Tool
120 bets on 7 selections covering every combination except singles.
Trixie Bet Tool
4 bets on 3 selections: 3 doubles and a treble — you need 2 winners to return.
Union Jack Patent Tool
Union Jack Patent: 9 selections in a 3x3 grid with a Patent on every line.
Union Jack Round Robin Tool
Union Jack Round Robin: 9 picks in a 3x3 grid with a Round Robin on every line.
Union Jack Trebles Tool
Union Jack Trebles: 9 picks in a 3x3 grid with 8 trebles along every line.
Union Jack Trixie Tool
Union Jack Trixie: 9 picks in a 3x3 grid with a Trixie on every line.
Yankee Bet Tool
11 bets on 4 selections: 6 doubles, 4 trebles and a four-fold — 2 winners needed.
Value & Strategy Tools
Margin Tool
Bookmaker margin (overround) on a two-way market, plus implied probabilities.
ROI Tool
Your betting return on investment from total staked, total returned and bet count.
Streak Tool
Probability of winning or losing streaks from your win rate and streak length.
Arbitrage Tool
Find guaranteed profit by backing every outcome across bookmakers — just enter the odds.
Closing Line Value Tool
Measure your edge by comparing your price to the closing line — the best long-term signal.
Dutching Tool
Split stakes across selections in one market for the same return whichever one wins.
Expected Value Tool
Check whether a bet is +EV from the odds and your estimated true probability.
Half Point Tool
Cost and value of buying half points on spreads — see if the extra juice is worth it.
Hold Tool
Bookmaker hold (vig) on any two-way market, with implied probabilities.
Kelly Criterion Tool
Find the optimal stake from your edge and bankroll — full, half and quarter Kelly.
Strike Rate Tool
Track your win percentage against the break-even rate for your average odds.
Surebet Tool
Guaranteed profit from surebets — enter prices from different bookmakers.
Win/Loss Tool
Track performance with win rate, ROI and profit per bet from your betting history.
Hedge & Cover Tools
Reverse Bet Tool
Payouts and profit/loss for a US if-bet reverse on two selections across every result.
Each-Way Bet Tool
Work out win and place returns on each-way bets from your stake, odds and place terms.
Hedge Bet Tool
Bet against your original wager to lock in profit or cap losses — get the exact hedge stake.
Middle Bet Tool
Spot middling chances where two opposing lines can both win, and size each side.
Specialty Tools
Forecast Bet Tool
Horse racing forecast (exacta) payouts from your two horses' odds and stake.
Over/Under Tool
Payouts for totals markets from the line, both prices and your stake.
Teaser Bet Tool
US teaser payouts for points moved (6, 6.5, 7, 10, 13) across your selections.
Tricast Bet Tool
Horse racing tricast (trifecta) payouts for three horses finishing 1st, 2nd and 3rd.
Asian Handicap Tool
Settle Asian handicap bets from the handicap, odds and final score.
Bonus Bet Tool
See the guaranteed profit you can pull from free and bonus bets, and the best lay odds.
Lay Bet Tool
Lay stake, liability and profit for exchange bets — find the lay that matches your back.
Matched Betting Tool
Best lay stakes for matched betting on qualifying bets and free bets (SNR and SR).
Poisson Tool
Predict scorelines and outcomes from each team's expected goals using the Poisson model.
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.