Implied Probability Calculator

Convert any odds format to its true implied probability. Reverse-convert any probability to American, decimal, and fractional odds.

Odds format
Implied probability
52.38%
1.91 decimal
Read the guide

American Odds: A Complete Guide

How to read +/- odds, the vig hidden in -110, converting to decimal and implied probability, and the mistakes most retail bettors make.

Read it
Related tools
Parlay Calculator
Multiply odds across legs.
Hedge Calculator
Lock in profit on a parlay.
Vig Remover
Strip the book's margin.
Kelly Criterion
Optimal bet size for your edge.
Bracket Generator
Build a tournament bracket.
Made To Parlay

We think in parlays. Multi-leg bets where every leg has to hit. The same logic powers our app: every day is a parlay of habits, and the streak only counts if every leg cashes.

See the app

Implied probability FAQ

What is implied probability?

Implied probability is the probability the odds suggest will happen, derived directly from the price. Decimal odds of 2.00 imply 50%. Decimal odds of 1.91 imply 52.4%. Formula: 1 / decimal odds.

Why is implied probability higher than the 'true' probability?

Sportsbooks build a margin (the vig or juice) into every line. The sum of implied probabilities on both sides of a market is always greater than 100%. Strip the vig and you get a closer estimate of the book's true probability. Use a vig remover to do this.

How do I convert American odds to implied probability?

Negative odds (e.g., -110): probability = |odds| / (|odds| + 100). So -110 → 110/210 = 52.4%. Positive odds (e.g., +150): probability = 100 / (odds + 100). So +150 → 100/250 = 40.0%.

How do I convert decimal odds to implied probability?

probability = 1 / decimal odds. Decimal 1.50 → 66.7%. Decimal 3.00 → 33.3%.

How do I convert fractional odds to implied probability?

probability = denominator / (numerator + denominator). 5/2 → 2/7 = 28.6%. 1/4 → 4/5 = 80%.