Calculate the probability of a parlay winning and the margin embedded in it.
Multiplying probabilities means adding legs reduces the win chance geometrically. Comparing fair odds with the odds offered reveals the margin, which compounds with each leg added. The independence assumption often fails in practice, since correlated legs such as two outcomes in the same match make the true probability differ from the product.
Parlay Probability
Parlay probability = the product of the individual probabilities, assuming independence
These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
Parlay probability = the product of the individual probabilities, assuming independence Multiplying probabilities means adding legs reduces the win chance geometrically. Comparing fair odds with the odds offered reveals the margin, which compounds with each leg added.
The independence assumption often fails in practice, since correlated legs such as two outcomes in the same match make the true probability differ from the product.
This calculator takes 5 inputs: Leg 1 true probability, Leg 2 true probability, Leg 3 true probability, Leg 4 true probability, 100 if unused, Combined odds offered. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.