An estimation device estimates a stroke quantity indicating a displacement in an up-and-down direction of a vehicle, in a multistage elastic member in which a plurality of members, each having a different load displacement characteristic indicating a relationship between a load and the displacement, are disposed. The estimation device comprises: a load calculation unit configured to calculate a variable ground contact load received by a wheel of the vehicle from a ground contact surface; a state quantity estimation unit configured to estimate the stroke quantity generated in the multistage elastic member; and a characteristic change unit configured to change a setting of the initial value to an estimated load displacement characteristic.