Odds Converter: American, Decimal, Fractional & Probability

Betting odds can display the same price in several formats. American odds are common at US sportsbooks, decimal odds are widely used internationally, and fractional odds remain familiar in UK and Irish betting markets. This calculator converts between American, decimal, fractional odds and implied probability. It also calculates profit, total return and the stake required to reach a target profit.

Quick examples: -110 equals about 1.91 decimal, 10/11 fractional and 52.38% implied probability. +150 equals 2.50 decimal, 3/2 fractional and 40% implied probability.

Betting Odds Converter

Convert American, decimal, fractional odds and implied probability without losing the value being typed.

Odds tool
Quick American-odds examples
Must be greater than 1.00.
Use +100 or higher, or −100 or lower.
Exact standard fraction.
%
Break-even probability for this price, before any no-vig normalization.

Payout and target-profit calculator

Currency changes the display symbol only; no FX conversion is performed.
$
Calculates the stake required to produce the entered profit.
Break-even probability 40.00% Your true win probability must exceed this threshold for positive expected value at the displayed price.
Profit if the bet wins $150.00
Total return $250.00
Stake required for target profit
American-price class Plus-money equivalent
Implied probability from one price does not remove bookmaker margin. Use every mutually exclusive side of the market in a no-vig or margin calculator.


What the Odds Converter Calculates

  • American to decimal: convert moneyline prices such as +150 or −200.
  • Decimal to American: convert total-return multipliers such as 2.50 or 1.67.
  • Fractional conversion: convert prices such as 5/2, 10/11 or evens.
  • Implied probability: calculate the break-even chance represented by one offered price.
  • Profit and total return: separate winnings from the returned stake.
  • Target profit: calculate how much must be staked to produce a chosen profit.
Same price, different notation: +150, 2.50 and 3/2 describe the same payout. Changing the format does not change the underlying value of the bet.

Common Odds Conversion Table

AmericanDecimalFractionalImplied probabilityProfit on $100Total return
−5001.201/583.33%$20.00$120.00
−2001.501/266.67%$50.00$150.00
−1501.672/360.00%$66.67$166.67
−1101.9110/1152.38%$90.91$190.91
+1002.001/150.00%$100.00$200.00
+1502.503/240.00%$150.00$250.00
+2003.002/133.33%$200.00$300.00
+4005.004/120.00%$400.00$500.00
+100011.0010/19.09%$1,000.00$1,100.00

American, Decimal and Fractional Odds Explained

American odds

Positive prices show the profit from a $100 stake. Negative prices show the stake required to win $100 profit.

+150: stake $100 → profit $150
−200: stake $200 → profit $100

Decimal odds

Decimal odds are the total-return multiplier, including the returned stake.

$100 × 2.50 = $250 total return
Profit = $250 − $100 = $150

Fractional odds

A fraction shows profit relative to stake. At 5/2, each 2 units staked produce 5 units of profit.

$100 × 5 ÷ 2 = $250 profit
Total return = $350

Odds Conversion Formulas

Positive American to Decimal

Decimal odds = 1 + (American odds ÷ 100)

Example: +150 becomes 1 + 150 ÷ 100 = 2.50.

Negative American to Decimal

Decimal odds = 1 + (100 ÷ |American odds|)

Example: −200 becomes 1 + 100 ÷ 200 = 1.50.

Decimal to American

If decimal ≥ 2.00: American = (decimal − 1) × 100
If decimal < 2.00: American = −100 ÷ (decimal − 1)

Fractional to Decimal

Decimal odds = 1 + (numerator ÷ denominator)

Example: 5/2 becomes 1 + 5 ÷ 2 = 3.50.

Decimal to Implied Probability

Implied probability = 1 ÷ decimal odds × 100

Example: 2.50 becomes 1 ÷ 2.50 × 100 = 40%.

Profit, Total Return and Target Profit

Profit is the amount won above the original stake. Total return is the profit plus the returned stake.

Profit = stake × (decimal odds − 1)
Total return = stake × decimal odds

At 2.50 decimal with a $100 stake:

  • profit = $100 × 1.50 = $150;
  • total return = $100 × 2.50 = $250.

To calculate the stake required for a target profit:

Required stake = target profit ÷ (decimal odds − 1)

Implied Probability and Break-Even Chance

The implied probability of one offered price is its break-even win rate. If 2.50 decimal implies 40%, a bettor's true probability estimate must exceed 40% for positive expected value at that price.

This does not mean the bookmaker's no-vig estimate is exactly 40%. The offered market normally contains margin, but the break-even threshold of the individual bet remains determined by its price.

Important distinction: break-even probability answers “how often must this bet win at this price?” No-vig probability answers “how should the full market be normalized after removing margin?” The second calculation requires every mutually exclusive outcome.

Why One Implied Probability Does Not Remove Vig

Bookmaker margin is measured across a complete market. In a two-way market, the raw implied probabilities of both sides usually sum to more than 100%. In a three-way soccer market, the home, draw and away probabilities may also exceed 100% when added together.

To estimate margin-free probabilities, enter all sides into the No-Vig Calculator. To measure the raw overround, use the Bookmaker Margin Calculator.

Which Odds Format Is Best?

No display format pays more by itself. The best available price is the one with the highest underlying decimal value after confirming that the markets, settlement rules and limits are equivalent.

For example, +150, 2.50 and 3/2 are the same price. A sportsbook offering 2.55 is better than one offering 2.50, regardless of whether the interface displays American, decimal or fractional notation.

Choose Another Odds Tool

The main converter handles all common formats. Use a dedicated tool when the task requires a full-market or one-direction calculation.

Probability and market margin

Convert probabilities or analyze every side of a market.

Charts and guides

Lookup tables, exports and worked payout explanations.


Frequently Asked Questions

What is an odds converter?

An odds converter changes one betting price into equivalent American, decimal, fractional and implied-probability formats. The payout does not change; only the notation changes.

How do I convert American odds to decimal odds?

For positive American odds, divide by 100 and add 1. For negative American odds, divide 100 by the absolute American number and add 1. For example, +150 becomes 2.50 and −200 becomes 1.50.

How do I convert decimal odds to American odds?

At 2.00 or higher, subtract 1 and multiply by 100. Below 2.00, divide −100 by decimal odds minus 1. Results are normally rounded to the nearest whole American price.

Why does the calculator show a nearest fractional price?

Sportsbooks use a conventional set of fractional prices. A rounded decimal value may not equal one of them exactly, so the calculator displays the nearest common fraction. For example, rounded 1.91 decimal is conventionally represented as 10/11.

What does +200 mean in betting?

+200 means a $100 stake produces $200 profit and $300 total return if the bet wins. It equals 3.00 decimal odds, 2/1 fractional odds and 33.33% implied probability.

What does −150 mean in betting?

−150 means a bettor must risk $150 to produce $100 profit. It equals about 1.67 decimal odds, 2/3 fractional odds and 60% implied probability.

What are even-money odds?

Even money means the profit equals the stake. It is displayed as +100 in American odds, 2.00 decimal and 1/1 or evens in fractional notation.

Does implied probability remove bookmaker margin?

No. One price gives the break-even probability of that bet. Removing margin requires all mutually exclusive outcomes in the market and a no-vig normalization method.

What is the difference between profit and total return?

Profit is the amount won above the original stake. Total return includes both the profit and the returned stake. A $100 bet at 2.50 returns $250 in total, of which $150 is profit.

Responsible gambling notice: Odds conversion does not establish that a bet has positive value. Your probability estimate can be wrong, and bookmaker rules, limits and settlement terms can differ. Never wager more than you can afford to lose. If gambling stops being entertainment, visit BeGambleAware in the UK or call 1-800-GAMBLER in the US.

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