CFTROU

Probability ↔ Odds Converter

Convert in either direction. Have a probability from any model (Poisson, your own estimate, anything) and want the fair American sportsbook price for it? Or have a sportsbook's odds and want to know the probability it implies? Both calculators below do the math, no goals or game context required.

Probability → odds

The formula

if p ≤ 50%: odds = (1 − p) / p × 100

if p > 50%: odds = −p / (1 − p) × 100

Plugged in for 25%:

odds = (1 − 25%) / 25% × 100

Odds → probability

The formula

if odds > 0: p = 100 / (odds + 100)

if odds < 0: p = −odds / (−odds + 100)

Plugged in for 300:

p = 100 / (300 + 100)

Odds to probability reference

OddsProbability
-100090.9%
-90090.0%
-80088.9%
-70087.5%
-60085.7%
-50083.3%
-40080.0%
-30075.0%
-20066.7%
-10050.0%
+10050.0%
+20033.3%
+30025.0%
+40020.0%
+50016.7%
+60014.3%
+70012.5%
+80011.1%
+90010.0%
+10009.1%

Need a probability first?

If you're working from a soccer team's expected goals rather than a probability you already have, the Soccer Poisson Goals & Odds Calculator will derive the probability for you from a Poisson model, then convert it the same way this page does.

How this is calculated

If probability ≤ 50%: American odds = (1 − p) / p × 100 (shown as +, an underdog price)

If probability > 50%: American odds = −p / (1 − p) × 100 (shown as −, a favorite price)

If odds > 0: implied probability = 100 / (odds + 100)

If odds < 0: implied probability = −odds / (−odds + 100)

Decimal odds = 1 / p

These are fair, no-margin odds implied directly by the probability. Real sportsbooks shade both sides to bake in their profit margin (the vig).