Erodability (or erodibility) is the inherent yielding or nonresistance of soils and rocks to erosion. A high erodibility implies that the same amount of work exerted by the erosion processes leads to a larger removal of material. Because the mechanics behind erosion depend upon the competence and coherence of the material, erodibility is treated in different ways depending on the type of surface that eroded.

Soil erodibility is a lumped parameter that represents an integrated annual value of the soil profile reaction to the process of soil detachment and transport by raindrops and surface flow. The most commonly used model for predicting soil loss from water erosion is the Universal Soil Loss Equation (USLE) (also known as the K-factor technique), which estimates the average annual soil loss ${\displaystyle A}$ as:

where R is the rainfall erosivity factor, K is the soil erodibility, L and S are topographic factors representing length and slope, and C and P are cropping management factors.

Other factors such as the stone content (referred as stoniness), which acts as protection against soil erosion, are very significant in Mediterranean countries. The K-factor is estimated as following

K = [(2.1 × 10⁻⁴ M^1.14 (12–OM) + 3.25 (s-2) + 2.5 (p-3))/100] * 0.1317

M: the textural factor with M = (m_silt + m_vfs) * (100 - m_c)

m_c :clay fraction content (b0.002 mm);

m_silt  : silt fraction content (0.002–0.05 mm);