1. A calculating apparatus that calculates a characteristic of a target signal, comprising: a designating section that receives a designation 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 by using a relational expression between the sampling timing and the bit error rate in a transmission model for transmitting a signal having jitter that includes a random component and a deterministic component having a prescribed probability density distribution, the relational expression achieved by substituting, as parameters, a standard deviation of a random component in jitter of the target signal and a peak-to-peak value of a deterministic component in the jitter of the target signal.