Expected Value Decision Explorer

Enter possible outcomes and their probabilities for two healthcare options. The explorer calculates probability-weighted expected values and applies the correct maximize or minimize decision rule.

What the explorer calculates

Expected value is the sum of each possible outcome multiplied by its probability. Probabilities within each option must total 100% before the results can be interpreted.

EV(X) = Σ pᵢxᵢ | Σpᵢ = 1

Set the decision context

Choose what the values represent and whether a larger or smaller expected value is preferred. Benefits, health outcomes, utility and net benefit are normally maximized; costs are normally minimized when outcomes are equivalent.

Outcome type Decision rule Unit

Enter possible outcomes

Each row represents one mutually exclusive outcome. Negative values may be used for losses, and every option must represent a complete set of outcomes.

Option A

Option B

Expected-value results

The result for each option is its probability-weighted mean, not its most likely individual outcome. The preferred option shown here follows only the selected expected-value rule and does not establish affordability, equity or adoption.

Option A expected value—Probability total: —

Option B expected value—Probability total: —

Enter valid inputs and calculate to compare the options.

Interpret carefully. Two options can have the same expected value but very different possible outcomes. Expected value summarizes the average and does not show the full distribution or uncertainty around it.

Option	Outcome	Probability	Value	Weighted value
No calculated results yet.