Moneyline Odds Calculator - Decimal, Fractional, Payout

A moneyline odds calculator reads the signed American price a US sportsbook prints on a game and turns it into the three other formats a bettor needs to compare lines, plus the payout and profit on a stake. Paste a positive number for an underdog, a negative number for a favorite, and read the decimal odds, fractional odds, implied probability, total payout, and net profit in one panel.

• • Read a US sportsbook line: Paste a signed American line like +150 or -200 and read the chance the book is implying for that outcome.
• • Compare US and European books: Convert the same American line into the decimal odds a European sportsbook would print on the same event.
• • Convert to UK fractional format: Read the same price as a profit-to-stake ratio a UK bookmaker would print, in reduced fractional form.
• • Size a moneyline bet: Set the stake to the amount you want to risk and read the total payout plus the net profit on a winning ticket.

If the book you usually read lists prices in UK fractional format, the Fractional Odds Calculator converts the same kind of profit-to-stake ratio that this calculator prints in reverse.

Branch on the sign of the American line, compute the decimal odds, the implied probability, and the reduced fractional ratio, then multiply the decimal odds by the stake to get the payout and the net profit.

• A: Signed American moneyline odds. Positive A is an underdog price that prints the profit on a 100 dollar stake, negative A is a favorite price that prints the stake needed to win 100 dollars profit.
• Decimal odds: A multiplier on the stake that includes the stake in the return. Decimal 2.50 on a 100 dollar stake returns 250 dollars total.
• Implied probability: The chance the sportsbook is implying. +150 implies 40 percent, -200 implies 66.67 percent, and +100 or -100 is the even 50 percent line.
• Fractional odds: The profit-to-stake ratio in reduced form. +150 becomes 3/2, -200 becomes 1/2, and +100 or -100 becomes 1/1.
• Payout and profit: Total payout is stake times decimal odds. Net profit is payout minus stake. Both print the same way on a US betting slip.

The same steps apply to any positive or negative line. A +400 long shot gives decimal odds of 5.00, an implied probability of 20 percent, and the fractional ratio of 4/1, which is the same profit-on-stake a UK bookmaker would print on that long shot.

According to Wikipedia Betting odds article, a positive American moneyline of A converts to decimal odds of 1 + (A / 100) and an implied probability of 100 / (A + 100), while a negative American moneyline of A converts to decimal odds of 1 + (100 / |A|) and an implied probability of |A| / (|A| + 100).

Once the decimal odds and the implied probability are in hand, the Implied Probability Calculator extends the same math to a two-way or three-way market by removing the bookmaker overround from a pair of opposing lines.

Four ideas cover everything you need to read any American moneyline line and check it against your own estimate.

The base stake convention is the same logic a US bettor reads on the betting slip, and the same logic that lets the calculator convert the line into decimal, fractional, and implied probability in a single step.

The implied probability on a moneyline is a single-event probability in the same sense the Probability Calculator handles, so the rules of complements, independent events, and conditional probability apply to a moneyline price the same way they apply to a coin flip.

Four steps take you from a US sportsbook screenshot to a decimal line, a fractional line, an implied probability, and a payout on your stake.

1. 1 Enter the American moneyline: Type the signed American price from the sportsbook. Use a positive number like 150 for an underdog, a negative number like -200 for a favorite.
2. 2 Set the stake: Enter the dollar amount you plan to risk. The default 100 dollars matches the standard US betting slip.
3. 3 Read the conversion outputs: Use the decimal odds and fractional odds to compare the line to European or UK books, and use the implied probability to compare the line to your own estimate.
4. 4 Read the payout and profit: Use the total payout and net profit to size the bet against your bankroll and the implied probability you read in the previous step.

A standard -110 line on a 100 dollar stake gives decimal odds of 1.91, fractional odds of 10/11, an implied probability of 52.38 percent, a total payout of 190.91 dollars, and a net profit of 90.91 dollars. If your own model gives the favorite a 55 percent chance of winning, the gap between your 55 percent and the implied 52.38 percent is the edge on the bet.

When the implied probability is reported as a percent, the Probability Fraction Calculator converts the same number to a fraction or a decimal so it drops into a Kelly criterion or a bankroll model.

Using a moneyline odds calculator instead of doing the conversion by hand changes how fast you read a US sportsbook line.

• • Convert any American line in one step: Paste a signed American line and read the decimal odds, fractional odds, and implied probability together.
• • Compare US and European prices: The decimal odds output is the format European and offshore books print, so a US bettor can compare prices across books on the same event.
• • Read UK fractional prices: The reduced fractional ratio output is the format UK bookmakers print, so a US bettor can read a fractional line without doing the math.
• • Check the implied probability: The implied probability output is the chance the book is implying, which a bettor compares to their own model to find an edge.
• • Size the bet on the same screen: The stake input plus the total payout and net profit outputs let the bettor size the bet without leaving the calculator.
• • Handle positive and negative lines the same way: The same workflow works for an underdog like +400 and a favorite like -250, covering the full range of US moneyline markets.

Five variables move the decimal odds, the implied probability, and the payout the most, and two caveats tell you when the calculator output needs a second look.

• • The calculator converts a single moneyline price, so it does not remove the bookmaker overround the way the implied-probability calculator does for a full two-way or three-way market. For a head-to-head matchup, paste the two opposing lines into the implied-probability calculator instead.
• • The payout and profit outputs assume the bet wins at full strength and does not push, void, or dead heat. Real US sportsbooks settle pushes and dead heats by refunding the stake, which the calculator does not model.

A single moneyline price carries more house edge than a no-vig two-way price, so a bettor who wants to find an edge on a matchup should also read the opposing line in the implied-probability calculator before sizing a bet.

According to American Gaming Association industry resources, US sportsbooks quote moneyline prices on a 100 dollar base stake so a positive line prints the profit and a negative line prints the stake needed to win the same 100 dollars of profit.

According to Wikipedia Moneyline article, a moneyline bet is a wager on the outright winner of a game with no point spread, the positive odds print the profit on a 100 dollar stake, and the negative odds print the stake needed to win 100 dollars profit.

Once the implied probability is fixed, the Binomial Distribution Calculator uses the same kind of per-trial probability to size a series of moneyline bets or count a streak of wins at a given edge.