AbstractCrack spacing is a governing parameter in predicting the crack width of reinforced concrete (RC) specimens. Recent studies have identified that the “no‐slip” theory is suitable for discussing the actual cracking behavior of RC specimens. Concrete cover (c) and the clear distance between tensile bars (s) are the governing crack spacing parameters, according to the “no‐slip” theory. The parameter s has not been considered in widely used crack spacing models including Eurocode. An experimental program has been conducted, using large‐scale RC specimens to investigate the behavior of c and s on crack spacings. These experiments have been numerically simulated with 3D nonlinear finite element models for the verification of results. The experimental results showed that both c and s have an influence on the crack spacings and therefore to the crack widths. An equation has been developed with multiple linear regression analysis, and its predations gave a good agreement with the experimental results in the literature.