How the calculator finds the decay rate

Exponential decay assumes the same percentage is lost each period. If the value starts at P and ends at A after t periods, the model is A = P(1-r)^t. Solving that equation isolates the decay rate r.

What the curve shows

The preview traces the full path from the starting amount to the ending amount. The highlighted point confirms that the recovered rate matches your supplied final value at the chosen time.

Common uses

This workflow is useful for depreciation, shrinking populations, radioactive decay approximations, and any repeated percentage drop where the beginning and ending values are known.