A recently introduced parameter, the ratio of an aggregate solid mass to a solid mass of an intraaggregate matrix
(K ratio) is connected with the mean thickness of a deformable, but non-shrinking surface layer of aggregates and is a
fundamental property of aggregated soils that essentially influences their shrinkage. The objective of this work is to suggest
and validate an approach to estimating the K ratio at any soil clay content through characteristics of soil texture and
structure. We derive an equation that reflects the interrelation between the K ratio and soil texture and structure. The K ratio
can be estimated as the solution of the equation and is determined by the mean size of soil solids and the maximum
size of soil aggregates in the oven-dried state, independently of a measured shrinkage curve. To validate the approach we
use available data for eight soils.