Thermodynamic properties of n-hexane have been calculated over a temperature range of 32° to 540°F. and up to a pressure of 600 lb./sq. in. abs. These properties were determined from vapor pressure, volumetric, heat capacity, and latent heat of vaporization data through the application of rigorous thermodynamic relationships. The calculated data have been found to be internally consistent. The enthalpy values are believed to be accurate to within 0.5 B.t.u./lb. and the entropy values to 0.0005 B.t.u./(lb.)(°R.).