Probability Calculator

Calculate probabilities for events and odds.

Calculate the probability of drawing specific items from a group.

Favorable Items

Total Items

Number of Draws

Without Replacement?

Probability

As Percentage

Fraction Odds

Fill in the fields, then press Calculate.

How probability works

With replacement — each draw is independent: P = (favorable/total) ^ choices.
Without replacement — each draw reduces the pool: multiply (favorable-i)/(total-i) for each draw.

Example: drawing 2 aces from a 52-card deck without replacement = (4/52) × (3/51) ≈ 0.45%.