What does the Probability Calculator work out?

Two independent events, together or either. It is one of the Math tools on Mondo Knows.

How is the Probability Calculator calculated?

You get an instant answer with the working shown underneath.

Do I need to sign up, and is my data stored?

No sign-up, and nothing you type is sent anywhere. The calculation runs in your own browser, so the figures stay on your device and the page works offline once loaded.

Mondo Knows Tools

Probability Calculator

Two independent events, together or either. Use the free probability calculator below to get an instant answer, with the formula shown so you can check the maths and trust the result. Free, private, and no sign-up.

Probability of A

Probability of B

Mondo says

Both happen (A and B)

15.00%

Either happens (A or B)65.00%

Neither happens35.00%

Odds of A1 to 1

Assumes the two events are independent of each other.

Probability Calculator: common questions

What does the Probability Calculator work out?: Two independent events, together or either. It is one of the Math tools on Mondo Knows.
How is the Probability Calculator calculated?: You get an instant answer with the working shown underneath.
Do I need to sign up, and is my data stored?: No sign-up, and nothing you type is sent anywhere. The calculation runs in your own browser, so the figures stay on your device and the page works offline once loaded.

Mondo also knows

Permutation and Combination CalculatorWays to arrange or choose from a set.➗ Math Random Number GeneratorFair random numbers in any range.➗ Math Pythagorean Theorem CalculatorSolve a right triangle's missing side.➗ Math Quadratic Formula CalculatorRoots of ax^2 + bx + c = 0, including complex ones.➗ Math

Facts that connect to the probability calculator

Short, sourced facts that point back to this tool.

Quantum particles exist in multiple states simultaneouslySubatomic systems remain in a superposition of probability states until measured

Estimates for general guidance only. This is not financial, medical or legal advice. Everything runs in your browser and nothing you type is stored.