This information deals with a computation methods of the least-squares method based on the influence coefficients for multi-plane balancing of flexible rotors. Applying the orthogonalization (QR decomposition) to the normal equation of the least-squares method, a personal computer programs is developed in the simple form on the computation languages and environment of Mathematica or MATLAB. This approach have higher accuracy rather than the conventional influence coefficient method and the normal equation without QR decomposition. It is expected that this personal computer based program is applicable to handy vibration measuring instrument set or hand held-computer.