This study proposes a method for estimating the meat volume of Pacific oysters (Crassostrea gigas) by using Helmholtz resonance. The meat volume was computed using the shell plus meat weight, meat density, shell density, and shell plus meat volume. The meat density was averaged from the combined weight and volume of 73 oysters. This average value was then used for calculating the meat volume of individual oysters. The shell plus meat weight and volume were measured by an electronic balance and Helmholtz resonance, respectively. The shell density was estimated using the calibration curve between the shell density and shell plus meat density. The measurement error in the meat volume was 2.5±2.6 mL (n＝56).