Odds converter: American, decimal and implied probability
Worked example
A prop priced at -110 is 1.909 in decimal odds and implies 52.4%. A price of +150 is 2.500 in decimal and implies 40.0%. Going the other way, decimal odds of 2.50 are +150 in American odds.
How it works
American odds are quoted per 100. A minus price such as -110 is how much you stake to win 100; a plus price such as +150 is how much you win on a 100 stake. Decimal odds are the total return per 1 staked, stake included, so -110 is 1 + 100/110 = 1.909.
Implied probability is 1 divided by the decimal odds. The converter rounds American odds to the nearest whole number, so a round trip can differ by a point or so.
Frequently asked questions
How do I convert American odds to decimal odds?
For a minus price, decimal odds are 1 plus 100 divided by the price without its minus sign, so -110 is 1.909. For a plus price, decimal odds are 1 plus the price divided by 100, so +150 is 2.5.
What does the implied probability field show?
It shows the chance the price suggests before any adjustment, which is 1 divided by the decimal odds. It includes the book's margin, so the two sides of a market add up to more than 100%.
Why do prediction markets look different from sportsbooks?
Prediction markets such as Kalshi and Polymarket quote a price that is already a probability. ArchivePicks converts those prices to American odds so every book reads the same way.
Does this tell me which side to take?
No. It only converts between formats. ArchivePicks does not take bets and does not say which side to take.
Related
- Implied probability calculator
- No-vig (fair odds) calculator
- Parlay calculator: combined odds and payout
- All odds calculators
- American odds in the Glossary
- Prediction Market Prices vs Sportsbook Odds: How to Compare Them
For information only. ArchivePicks does not take bets and does not tell you which side to take.