A battery-assisted bicycle that assists a pedal effort of a rider with driving force from an electric motor, comprising: a motor control part configured to control driving of the electric motor in accordance with the pedal effort; a battery configured to supply electricity to the electric motor; a battery control part configured to determine a remaining level of the battery; an assistable distance calculating part (111b, 151) configured to calculate a remaining assistable distance based on the remaining level of the battery determined by the battery control part; and a display configured to indicate the assistable travel distance calculated by the assistable distance calculating part (111b, 151), the motor control part being configured so as to be capable of changing a proportion of assistance of the electric motor to the pedal effort, wherein an assist mode corresponds to the proportion of assistance of the electric motor and the assist mode is selectable through an operation of an assist mode operation part, the assistable distance calculating part (111b, 151) being configured to calculate the assistable travel distance in accordance with the change of the proportion of assistance in the motor control part; characterized in that the assistable distance calculating part (111b, 151) is configured to calculate the assistable travel distance by using the amount of remaining electricity that is obtained by multiplying the nominal capacity and the proportion of remaining level of the battery, wherein the proportion of remaining level refers to the proportion of the remaining battery level relative to the battery level attained when the battery is fully charged, and an electricity consumption rate that is a travel distance per unit amount of electricity of the battery and is determined in accordance with the proportion of assistance, and the electricity consumption rate is a constant value obtained by dividing a travel distance in the respective assist mode attainable with the battery, when it is fully charged, by nominal capacity of the battery. a motor control part configured to control driving of the electric motor in accordance with the pedal effort; a battery configured to supply electricity to the electric motor; a battery control part configured to determine a remaining level of the battery; an assistable distance calculating part (111b, 151) configured to calculate a remaining assistable distance based on the remaining level of the battery determined by the battery control part; and a display configured to indicate the assistable travel distance calculated by the assistable distance calculating part (111b, 151), the motor control part being configured so as to be capable of changing a proportion of assistance of the electric motor to the pedal effort, wherein an assist mode corresponds to the proportion of assistance of the electric motor and the assist mode is selectable through an operation of an assist mode operation part, the assistable distance calculating part (111b, 151) being configured to calculate the assistable travel distance in accordance with the change of the proportion of assistance in the motor control part; characterized in that the assistable distance calculating part (111b, 151) is configured to calculate the assistable travel distance by using the amount of remaining electricity that is obtained by multiplying the nominal capacity and the proportion of remaining level of the battery, wherein the proportion of remaining level refers to the proportion of the remaining battery level relative to the battery level attained when the battery is fully charged, and an electricity consumption rate that is a travel distance per unit amount of electricity of the battery and is determined in accordance with the proportion of assistance, and the electricity consumption rate is a constant value obtained by dividing a travel distance in the respective assist mode attainable with the battery, when it is fully charged, by nominal capacity of the battery.