UtilityBaseCalculators
Betting Odds Converter
Convert between American, decimal, and fractional odds, with implied probability and payout.
Updated July 13, 2026
How to use the betting odds converter
- 1Pick the format of the odds you have, American, decimal, or fractional.
- 2Type the odds; the other formats and implied probability update instantly.
- 3Enter your stake to see profit and total return.
- 4Compare prices quoted in different formats across sportsbooks.
Common uses
- Comparing a US sportsbook (+150) to a European one (2.50)
- Finding the implied probability behind a price
- Checking the payout on a stake before betting
- Reading fractional odds from a UK bookmaker
Frequently asked questions
How do I convert American odds to decimal?
For positive American odds: decimal = (odds ÷ 100) + 1, so +150 becomes 2.50. For negative: decimal = (100 ÷ |odds|) + 1, so −200 becomes 1.50. This tool does it both ways automatically, along with the fractional form.
What is implied probability?
It's the win chance the odds assume, equal to 1 ÷ decimal odds. Decimal 2.50 implies 40% (1 ÷ 2.50). It's called 'implied' because sportsbooks add a margin (the vig), so the implied probabilities of all outcomes in an event sum to more than 100%. The overround is the book's edge.
How is the payout calculated?
Total return = stake × decimal odds; profit = stake × (decimal − 1). A $10 bet at 2.50 returns $25 total ($15 profit). Fractional odds show the profit ratio directly: 6/4 means $6 profit for every $4 staked.
About this tool
The odds converter takes any price in American (+150, −200), decimal (2.50), or fractional (6/4) format and instantly shows the other two, plus the implied probability the price assumes and the payout on a stake you choose. Implied probability is 1 ÷ decimal odds, the break-even win chance baked into the number. Enter your stake to see the profit and total return. It's a clean, instant converter for comparing prices across sportsbooks that quote different formats, with no sign-up. This is odds arithmetic, not betting advice.
Like most tools on UtilityBase, the betting odds converter runs entirely in your browser. Nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more calculators here.
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