Statistics & probability
Probability & odds converter
Translate an event probability into mathematical odds for and against.
A clear answer. Here’s how.
Odds in favour = p/(1−p); odds against = (1−p)/p. Reports probability and complementary probability alongside both ratios. At p=0 or p=1, the corresponding infinite ratio is labelled explicitly. These are mathematical odds, without fees, pricing margins or any wagering transaction.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Event probability (0–1)
- 0.2
Example result
- Event probability
- 0.2
- Complement probability
- 0.8
- Odds in favour
- 0.25 : 1
- Odds against
- 4 : 1