Concerning the evaluation of vibration with regard to ship habitability, for overall frequency-weighted root mean square (RMS) acceleration, the frequency-weighted function is deduced, which is expressed as the product of three factors (high-pass filter, low-pass filter, and pure weighting function), and the filter is designed based on this function. According to the frequency weighting curve from the standard, a low-order continuous-time filter is designed by the optimal least-square method. The one-third octave filter is proposed and the designed progress is given. The method is applied to ship test acceleration data, because accelerometers are the most frequently used transducers to measure the vibration responses of structures, and then the overall frequency-weighted RMS acceleration is achieved, which agrees well with the standard filter and low-order continuous-time filter results.