In forestry, a classical method of evaluating the profitability of an outlay is to calculate the internal rate of return. If there are many outlays and returns over a period, analytical determination of the internal rate is difficult and requires simulation methods. However, if there is only one outlay and one return, the computation is easy. In this paper, some formulae were developed for practical purposes. The equations also show how the return changes as the ratio between the return and the outlay changes.
The PDF includes a summary in English.