Abstract: A calibrating device, for measuring and calibrating a center of gravity of a remote control aircraft or an airfoil thereof, includes a crossbar, a first support, a second support and a control unit. The crossbar is arranged along a longitudinal axis, and includes a longitudinal rail and a slider. The slider is movably engaged with the longitudinal rail. The crossbar includes a drive member coupled with the longitudinal rail or the slider. The slider includes a pointer. The first support includes a seat and two receiving portions which are arranged on the seat and are movable along a transverse axis. The receiving portions are aligned with each other. Each receiving portion includes a load cell. The second support includes a base and a supporting portion, and the supporting portion includes a load cell. The control unit is coupled with the drive member and the three load cells.