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The soil‐air permeability (k_a) and its dependency on air‐filled porosity (ε) govern convective air and gas transport in soil. For example, accurate prediction of k_a(ε) is a prerequisite for optimizing soil vapor extraction systems for cleanup of soils polluted with volatile organic chemicals. In this study, we measured k_a at different soil‐water matric potentials down to 5.6‐m depth, totaling 25 differently textured soil layers. Comparing k_a and soil‐gas diffusivity (D_p/D₀) measurements on the same soil samples suggested an analogy between how the two soil‐gas transport parameters depend on ε. The exponent in a power‐law model for k_a(ε) was typically smaller than for D_p(ε)/D₀, however, probably due to the influence of soil structure and large‐pore network being more pronounced for k_a than for D_p/D₀ In analogy to recent gas diffusivity models and in line with capillary tube models for unsaturated hydraulic conductivity …