1. A calculating apparatus that calculates a characteristic of a target signal, comprising: an input section that receives an input of either a bit error rate or a sampling timing; and a calculating section that calculates a range of sampling timings over which the bit error rate is less than a designated value or a bit error rate at a designated sampling timing, wherein the calculating section employs a relational expression between the sampling timing and the bit error rate in a transmission model for transmitting a signal, wherein the signal has jitter including a random component and a deterministic component having a prescribed probability density distribution, and wherein the relational expression is achieved by substituting, as parameters, a standard deviation of a random component in the jitter of the target signal and a peak-to-peak value of a deterministic component in the jitter of the target signal.