Viscosities of commercial samples of skim milk, 1% fat milk, 2% fat milk, whole milk, half and half, and whipping cream were measured in a temperature range of 0 to 30°C by a coaxial viscometer. Viscosity varied exponentially with temperature and linearly with fat content of milk. Viscosity for the fat and temperature range measured varied from 1 to 60 centipoise. Density of these products also was determined by vibrational densitometer. Density ranged from 990 to 1035 kg/m3. The following equation was developed for the relationship between viscosity (μ), fat (F), and temperature (T): In μ = −8.9 + .1 F + 2721.5/T. The equation was utilized to calculate pumping requirements of milk with various fat contents and at different temperatures.