An optical transmission device includes: a serializer and deserializer configured to convert an input client signal into parallel data at a sampling rate of k times (k is a power of 2) a rate of the input client signal and output the parallel data; a frame generation section configured to generate an optical channel payload unit (OPU) frame from the client signal; and a stuff control section connected to an output of the parallel data and configured to perform, in units of 1/k bits, a stuff operation to map the client signal into the OPU frame and thereby calculate a Cn(n=1/k) value which is a theoretical value of the stuff operation.