Measurements are reported of the liquid and liquid-solid mixture (mush) densities of succinonitrile-acetone (SCN-ACE) alloys for use in crystal growth and solidification studies. The measured data for the liquid is analyzed and consolidated into a correlation that expresses the liquid density as a function of composition and temperature. This correlation also allows for the calculation of the thermal and solutal coefficients of volume expansion for liquid SCN-ACE alloys. Using the measured results for the liquid-solid mixture densities, the solid densities of SCN-ACE alloys during solidification in a mushy mode are estimated based on either the Lever or Scheil solidification model, and are found to be close to solid densities for pure SCN.