A calculation method comprising: calculating, by a processor , a difference between a first value and a second value, the first value being read from a clock counter that counts pulses of a clock signal having a plurality of types of frequencies, supplied to the processor in response to control command to start processing for an unit to be allocated to the processor , the second value being read from the clock counter in response to control command to stop processing, storing, in a storage device , the calculated difference in association with identification information that identifies the unit, calculating a difference between a third value and a fourth value, the third value being read from the clock counter in response to control command to start processing further performed when processing of the unit is to be further performed, the fourth value being read from the clock counter in response to control command to stop the processing that has been controlled to start; storing in the storage device , an incorporated value in association with the identification information, the incorporated value being obtained by adding the difference calculated based on the third value and the fourth value to the difference stored in the storage device in association with the identification information, calculating a difference between a fifth value and a sixth value, the fifth value being read from the clock counter in response to control command to start processing of another unit when processing of the other unit is to be performed, the sixth value being read from the clock counter in response to control command to stop the processing of the other unit; and storing, in the storage device , when the other unit is a unit for a program that is the same as the program of the unit, a sum of the incorporated value and the difference calculated based on the fifth value and the sixth value, in association with program identification information that identifies the program. calculating, by a processor , a difference between a first value and a second value, the first value being read from a clock counter that counts pulses of a clock signal having a plurality of types of frequencies, supplied to the processor in response to control command to start processing for an unit to be allocated to the processor , the second value being read from the clock counter in response to control command to stop processing, storing, in a storage device , the calculated difference in association with identification information that identifies the unit, calculating a difference between a third value and a fourth value, the third value being read from the clock counter in response to control command to start processing further performed when processing of the unit is to be further performed, the fourth value being read from the clock counter in response to control command to stop the processing that has been controlled to start; storing in the storage device , an incorporated value in association with the identification information, the incorporated value being obtained by adding the difference calculated based on the third value and the fourth value to the difference stored in the storage device in association with the identification information, calculating a difference between a fifth value and a sixth value, the fifth value being read from the clock counter in response to control command to start processing of another unit when processing of the other unit is to be performed, the sixth value being read from the clock counter in response to control command to stop the processing of the other unit; and storing, in the storage device , when the other unit is a unit for a program that is the same as the program of the unit, a sum of the incorporated value and the difference calculated based on the fifth value and the sixth value, in association with program identification information that identifies the program. <EOS>