To provide a calculating apparatus for bicycles which prevents the appearance a bicycle from being damaged by cords and can grasp the running distance or the like at an optical point desired by a user.

The apparatus has a calculating apparatus main body part 7 which comprises a speed sensor 2 set to a bicycle, a transmitter 3 connected to the speed sensor 2 for transmitting speed information as waves, a receiver 4 mounted detachably to the bicycle for receiving waves from the transmitter 3, a decoder 5 for decoding received signals and a display part 6 for displaying decoded data. The decoder 5 is provided with any one or a complex of (1) a speed calculation part for calculating a speed of the bicycle, (2) a distance calculation part for calculating a run distance of the bicycle and (3) a calory calculation part for calculating a consumed calory of a driver.