How to use this calculator

Multiply each outcome by its probability and add the products.

The method

E(X) = Σxᵢpᵢ

Enter your values in the labeled fields and choose Calculate. The result panel shows the answer and supporting values when useful.

WORKED EXAMPLE INPUT

Outcome values: 0, 10, 25, Probabilities: 0.2, 0.5, 0.3

Select Calculate to evaluate these example values.

Scope and limitations

Probabilities should be nonnegative and total approximately 1.

Common questions

Can I change the example values?

Yes. Replace every prefilled value with your own inputs and calculate again.

Are displayed results exact?

Some results are rounded for readability. Keep extra precision when the next step depends on the result.

Methods & verification

Formulas use standard mathematical definitions and fixed unit factors where applicable. See our methodology for numerical conventions, rounding, privacy, and limitations.