In this article, we provide a numerically solved linear relation between the total effective rotational correlation time of protein backbone N-H bonds, τ eff , and experimentally detectable transverse spin relaxation rate R2. This enables rapid interpretation of protein and peptide rotational dynamics directly from R2 values measured in one magnetic field without further modeling. Our results are valid for a wide range of systems that are beyond the scope of standard methods used to interpret molecular dynamics from spin relaxation experiments, from short peptides in water and micelles to large multi-domain proteins with disordered The magnitude of chemical exchange term at 500 MHz from our analysis and literature .