Probability · Betting

Odds Calculator

Type odds in any format — American, decimal, fractional or implied probability — and instantly get all the others, plus your exact profit and payout for a given stake.

American odds

e.g. +150 or -120

Decimal odds

e.g. 2.50

Fractional odds

e.g. 3/2 or 6/4

Implied probability (%)

e.g. 40 = 40%

Stake ($)

Return on a $100 bet

total payout (stake + profit)—

Stake returned—

Profit if it wins—

Total payout—

American

—

Decimal

—

Fractional

—

Implied probability

—

Fair probability

—

without bookmaker margin

Conversions

Decimal = 1 + profit/stake American ≥ 0 ⇒ (d−1)×100 American < 0 ⇒ −100/(d−1)

Implied probability is simply 1 ÷ decimal odds. American odds of +150 mean a $100 bet wins $150; odds of −150 mean you must stake $150 to win $100. The bookmaker’s margin is the excess over 100% when you sum the implied probabilities of every outcome.

🖌 All formats

American, decimal, fractional and implied probability update live whichever you type.

💰 Exact payout

See profit and total return for any stake, including negative-American-odds math.

🥈 Margin aware

Spot the “fair” probability once the bookmaker edge is stripped out.

⚡ Instant

Every keystroke recalculates all four odds and the money numbers.

Stack the odds in your favour

Combine multiple bets and see the true price.

Parlay Calculator