Sports Betting Calculator
Convert odds between decimal, American, and fractional formats and calculate exact payout for any stake. Use it before placing a bet to verify potential returns and compare value across bookmakers.
About this calculator
The payout formula depends on the odds format. For decimal odds: payout = stake × odds (e.g. $10 × 2.50 = $25 total return, including stake). For American odds, positive lines mean underdogs: payout = stake × (odds / 100) + stake (e.g. +150 means $10 wins $15, returning $25). Negative American odds indicate favourites: payout = stake × (100 / |odds|) + stake (e.g. −200 means $10 wins $5, returning $15). For fractional odds (e.g. 3/2 expressed as a decimal ratio): payout = stake × (odds + 1). Profit is always payout minus the original stake. Understanding these conversions is essential because bookmakers use different formats across regions — decimal in Europe, American in the US, fractional in the UK — and odds represent the bookmaker's implied probability, which includes a margin (the 'vig' or 'juice').
How to use
Suppose you want to place a $50 bet on American odds of +200. Since the odds are positive: profit = $50 × (200 / 100) = $50 × 2 = $100. Total payout = $100 + $50 stake = $150. Now compare with decimal odds of 3.00 (equivalent): payout = $50 × 3.00 = $150 — identical. For a favourite at −150: profit = $50 × (100 / 150) = $33.33; total payout = $83.33. Select your odds format, enter stake and odds value, and the calculator returns profit and total payout side by side.
Frequently asked questions
What is the difference between decimal, American, and fractional betting odds?
All three formats express the same underlying probability but in different conventions. Decimal odds (common in Europe and Australia) show total return per unit staked including the stake itself — odds of 2.0 doubles your money. American odds show profit relative to a $100 unit: +200 means $200 profit on $100 staked, while −200 means you must stake $200 to profit $100. Fractional odds (traditional in the UK) show profit relative to stake as a fraction — 2/1 means $2 profit per $1 staked. Converting between them is straightforward once you understand each baseline.
How do I calculate the implied probability from betting odds?
Implied probability tells you what winning chance the bookmaker has priced in. For decimal odds: probability = 1 / odds × 100%. For positive American odds: probability = 100 / (odds + 100) × 100%. For negative American odds: probability = |odds| / (|odds| + 100) × 100%. If decimal odds are 2.50, implied probability = 1/2.50 = 40%. If the true probability is higher than 40%, the bet has positive expected value. Bookmakers build in a margin (the overround) so that all outcomes sum to more than 100%, guaranteeing long-term profit for the house.
When should I use an each-way bet and how does the payout differ?
An each-way bet is two bets in one: a win bet and a place bet of equal stakes. If the selection wins, both bets pay out; if it places (typically top 2–5 depending on field size), only the place portion pays, usually at a fraction (commonly 1/4 or 1/5) of the win odds. This makes each-way betting popular in horse racing and golf where large fields make outright wins less likely. The total stake doubles because you are placing two separate bets, so factor that into your return calculation. This calculator covers single straight bets; for each-way, apply the formula twice with the adjusted place odds.