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Convert between decimal, American, fractional, and implied probability instantly. Type any field and the rest update live.
Type in any field - the rest convert instantly.
Total return per $1
US moneyline
UK profit:stake
Win chance %
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Get StartedEstimated typical sports margin by book - illustrative industry ranges, not Spindex-measured.
An odds converter turns any betting price into every other format at once - decimal, American (moneyline), fractional, and implied probability. Different sportsbooks and regions quote odds differently, so a converter is essential for comparing prices, understanding payouts, and seeing the true win probability behind a line.
American odds use a plus or minus sign. To convert positive American odds to decimal, divide by 100 and add 1 - so +150 becomes 150/100 + 1 = 2.50. To convert negative American odds, divide 100 by the number (ignoring the sign) and add 1 - so -200 becomes 100/200 + 1 = 1.50. To go the other way, decimal odds of 2.00 or more become positive American odds via (decimal - 1) x 100, and decimals under 2.00 become negative odds via -100 / (decimal - 1).
Implied probability is just 1 divided by the decimal odds, shown as a percentage. Decimal 2.00 equals a 50% implied probability, 1.50 equals 66.7%, and 4.00 equals 25%. This is the most useful conversion for bettors, because it translates a confusing price into a plain win chance you can compare against your own estimate of the true probability.
All three describe the same bet. Decimal odds (2.50) show the total return per $1 staked and are the easiest for quick math. American odds (+150 / -200) are the US standard, where positive numbers show profit on a $100 bet and negative numbers show the stake needed to win $100. Fractional odds (3/2) are common in the UK and show profit relative to stake. Our converter displays all of them - plus implied probability - the instant you type into any field.
Type a value into any of the four fields - decimal, American, fractional, or implied probability - and the other three update instantly. The tool also shows your return on $10, $50, and $100 bets so you can see the payout at a glance. It's free, runs in your browser, and is handy for comparing US sportsbooks against crypto books that display odds in different formats.
For positive American odds, divide by 100 and add 1 (e.g. +150 -> 150/100 + 1 = 2.50). For negative American odds, divide 100 by the absolute value and add 1 (e.g. -200 -> 100/200 + 1 = 1.50). This converter does it instantly in both directions.
For decimal odds of 2.00 or higher, subtract 1 and multiply by 100 for the positive price (2.50 -> +150). For decimals below 2.00, divide -100 by (decimal - 1) for the negative price (1.50 -> -200).
Implied probability is 1 divided by the decimal odds, expressed as a percent. Decimal 2.00 is a 50% implied probability; 1.50 is 66.7%. For American odds, convert to decimal first, then apply the same formula.
Implied probability is the win chance baked into a price - the bookmaker's estimate of how likely an outcome is, including their margin. It's the bridge between odds and value: if you think the true chance is higher than the implied probability, the bet has positive expected value.
They're three formats for the same price. Decimal (2.50) shows total return per $1 staked, American (+150 / -200) is the US moneyline format, and fractional (3/2) shows profit-to-stake and is common in the UK. This tool shows all three plus implied probability at once.
Decimal odds make payouts and probability easy to read at a glance - your return is simply stake times the decimal, and the implied probability is 1 divided by it. Most crypto sportsbooks and sharp tools default to decimal for that reason.
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