math calculator

Probability Calculator

Calculate the likelihood of an event happening. Simple yet powerful for games, risk assessment, statistics or everyday decisions like coin flips and lottery odds.

Important Use Notice

Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.

Estimate

Enter job values, review the estimate, then use the decision hints before ordering or quoting.

Number of favorable outcomes

Total number of possible outcomes

Estimate Results

Enter values to see the result.

Example

6 favorable out of 36 dice combinations → 6/36 = 0. 1667 (16. 67%)

Formula

P(Event) = Number of Favorable Outcomes / Total Possible Outcomes

Probability ranges from 0 to 1. Multiply by 100 for percentage.

For independent events: P(A and B) = P(A) × P(B)

Check

Confusing probability with odds (odds = probability / (1 - probability))
Confirm that all inputs use the same unit system expected by the formula.

Next Step

FAQ

What is the difference between probability and odds?

Probability is chance (0–1), odds is ratio of success to failure (e. g. 1:5 odds = 1/6 probability).

Can probability be greater than 1?

No — if calculation gives >1, check your inputs (favorable cannot exceed total).