Apparent thermal expansion measurements were carried out by dilatometry on eleven types of milk, grouped in three sets according to their fat to solids-not-fat ratio, over the temperature range of 0 degrees to 80 degrees C. Analytical expressions relating milk thermal expansion coefficients with its composition and temperature are given. These expressions predicted the thermal behaviour of samples usually within 1%. A nomogram is also presented for the direct derivation of relative integral dilatations from temperature, total solids content and fat to solids-no-fat ratio of the sample.