The increased sophistication of hydraulic systems along with the advancement of elastohydrodynamics and high pressure metal forming techniques has created a need for more complete bulk moduli and P-V-T data. By correlation of the available data on silicones, a generalized relationship for this class of fluids is determined for bulk modulus as a function of pressure, temperature, and density of the fluid at atmospheric pressure and 77F. Thus, density and bulk modulus for most silicone fluids may be predicted at temperatures from 32F to 400F and pressures up to 500,000 psig. For most silicone fluids only the density at atmospheric pressure and 77F is needed beforehand. A few exceptions are listed for which the correlation is applicable with minor modifications. The average deviation of the predicted values of bulk moduli from the experimental data is 1%. Presented at the 23rd ASLE Annual Meeting in Cleveland, May 6–9, 1968.