The relationships between soil components and soil physical contents were investigated on 94 soil samples varying widely in physical compostion. The soil components used were fine sand, very fine sand, silt, clay organic matter and calcium carbonate content. These were related to apparent density, field capacity, permanent wilting percentage, available moisture (dry weight basis), available moisture (volume fraction) and moisture retained at 1/4, 1/3, 1/2, 1, 3, 7 and 15 atmospheres tension by multiple regression analyses. The relationships were subsequently tested on 18 soil samples from sites not previously investigated. The results presented show that a highly significant relation exists between soil components and every soil physical constant. A detailed discussion of the extent and nature of each relationship and its usefulness for prediction purposes is given. A comparison of the errors in prediction in the 'test' soils and in the soils used to derive the relations is also given.