Read a Price

Read the Sign

Positive American odds state the profit on a $100 stake. Negative odds state the stake required for $100 profit. The sign changes the notation, not the arithmetic of returning the original stake after a win.

Turn the Price Into a Rate

At +150, decimal odds are 2.50: a winning $10 bet returns $25. The break-even rate is 1 ÷ 2.50 = 40%. That is the rate implied by the price, not a measured probability of the event.

Keep the Assumption Visible

A price can be internally consistent and still offer poor value. Assessing value requires a probability estimate that the converter cannot supply. Fees and settlement rules can also change the calculation.