<p>Diffuse ultrasound is a promising technique for estimating the depth of surface-breaking cracks in concrete. However, practical use in the field has been limited by the necessity of establishing the crack depth-lag time relationship, only derived by time-consuming finite element simulations. Running these time-consuming simulations on-site is impractical, especially when rapid assessment of damage over large areas is crucial. This research addresses this limitation by recently proposed theoretical diffuse energy velocity concepts, to directly correlate with depth of surface-breaking cracks. Existing datasets for artificial notches in concrete specimens and actual surface-breaking cracks in reinforced concrete beams subjected to four-point bending are utilized to evaluate the performance of the proposed method. The results indicate that the diffuse ultrasonic method based on the diffuse energy velocity provides more accurate crack depth predictions compared with conventional approaches. More importantly, the simplicity of using the theoretical diffuse energy velocity approach eliminates the need for time-consuming finite element simulations, enabling rapid, on-site crack depth measurements. This enhancement significantly improves the utility of the diffuse ultrasonic method for field applications. Therefore, this research highlights the potential of the diffuse ultrasonic method, enhanced by the theoretical diffuse energy velocity approach, to serve as a reliable and efficient commercial tool for field inspections of concrete structures.</p>