Statistics
Expected Value Calculator
Use the expected value calculator for probability tables, games of chance, decision analysis, and class homework.
Use decimals that add to 1, such as 0.25.
Try an example
Result
Expected value
—
- Probability sum
- —
Student quick launch
Grade planning, algebra checks, and formulas students reach for most.
Study path
Use this calculator with
Follow these when you want the formula behind the answer, a short lesson, or nearby tools in the same topic.
What the expected value calculator solves
Use the expected value calculator for probability tables, games of chance, decision analysis, and class homework.
Formula
How to use it
- Enter outcomes in one list.
- Enter matching probabilities as decimals.
- Check that probabilities add to 1.
How to read the answer
Expected value is the long-run average outcome under the probability model.
Common mistakes and edge cases
- Use decimals, not percent numbers, unless converted.
- Probabilities should match outcomes in order.
- Expected value may not be an outcome that can actually happen once.
Worked examples
Simple prize table
Expected value
5
Fair die
Expected value
3.5007
Frequently asked questions
Can expected value be negative?+
Yes, if losses or costs are included as negative outcomes.
Does expected value predict the next result?+
No. It describes the average over many repetitions.
Why check the probability sum?+
A probability table should usually account for all possible outcomes, so the probabilities should add to 1 before the expected value is trusted.
About this calculator
- Written by
- mathcheck editorial team
- Last reviewed
- May 15, 2026
Method
- Uses the values entered by the user and stable formulas documented on the page.
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Last updated: May 15, 2026