Wager Whistle / free tools

Transparent inputs. No locks.

Calculate the value behind a wager.

Plug in the American odds, the amount you would risk, and your own probability estimate. This calculator shows what those assumptions imply—it does not predict the result.

Input board / 01
Model the wager

Use a line like +110 or -110.

Enter the amount you would risk, not a target return.

%

Your estimate, from 0% through 100%—not a prediction from Wager Whistle.

Output / expected value
Your result will land here

Enter a line, a stake, and your probability estimate to see what your assumptions imply over many comparable wagers.

Read the number

EV is an estimate built on your estimate.

The calculation compares your win probability with the price in the line. Positive modeled value means your assumptions imply a gain over many similar wagers; negative value means they imply a loss. A single result can still go either way.

Nothing here predicts an outcome or guarantees a return. Bet only within your limits, and take a break if betting stops feeling recreational.
Read the responsible-betting guidance