A vehicle management device includes one or more processors configured to: manage a plurality of vehicles to be provided for users in a car sharing service; manage, as a plurality of first vehicles, a part of the vehicles to be allocated to an on-demand use in which the users use the car sharing service without reservation; manage, as a plurality of second vehicles, a part of the vehicles to be allocated to a reservation use in which the users use the car sharing service with the reservation; and change at least one of the second vehicles to the first vehicles when the number of the first vehicles is less than a first predetermined number.