KUNKAFA FREE PROBABILITY TOOLS

Scenario Expected Value Calculator by Kunkafa

Compare several possible outcomes with explicit probabilities, payoffs and costs. Kunkafa’s free expected value calculator shows how each assumption contributes to the average.

Define a complete set of scenarios

One row per outcome, up to 100. Use 50 for 50%. Payoffs are profit or loss, not total account balances. Probabilities must add to 100%. The optional header is probability,payoff.

Illustrative assumptions, not Kunkafa forecasts. Exactly one scenario must happen, and the rows must cover every possibility.

Why Kunkafa price-level probabilities cannot simply be added

Your scenario results

Expected net payoff
$60.00
Lowest possible net payoff
-$110.00
Highest possible net payoff
$190.00
Assumed chance of net loss
50.00%
Each scenario’s contribution to the expected net payoff
ScenarioProbabilityNet payoffWeighted contribution
150%$190.00$95.00
230%-$110.00-$33.00
320%-$10.00-$2.00

Expected value is a probability-weighted average, not an outcome promised for one decision. Zero-probability rows are excluded from the possible payoff range.

How expected payoff is calculated

Subtract the entered costs from every gross payoff, multiply each net payoff by its probability, then add those contributions. In the example, 50% × $190 + 30% × −$110 + 20% × −$10 = $60 expected net payoff.

Costs are charged once in whichever outcome happens. For different costs by scenario, enter already-net payoffs and set the shared costs field to zero. Include fees, spread, borrowing and other costs you want modeled; none are fetched automatically.

Do not add overlapping market probabilities

A market can reach both an upper and a lower price during the same duration. Those price-touch events overlap and are not a complete set of mutually exclusive outcomes. You cannot paste their individual probabilities into this table and interpret the result as a valid trade expectation.

Instead define outcomes with precise, non-overlapping rules, such as which exit happens first, and account for paths where neither exit happens. The probabilities for those particular rules still need evidence. This calculator cannot infer them from price-touch probabilities.

A positive average does not remove risk

Expected payoff does not show the sequence of results, maximum drawdown, capital requirements or reliability of the probabilities. One decision can lose money even when its assumed expected value is positive. Probability totals differing from 100% by no more than 0.00000001 percentage points are normalized to absorb floating-point rounding only.

Kunkafa adds predicted changes, direction and probabilities to market research. Use Kunkafa’s forecast methodology to understand what an output means before connecting it to a payoff model.

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