Carbon aromaticities for a selection of 19 bituminous coals and vitrinite concentrates have been obtained by solid-state 13C n.m.r. using the inherently quantitative single pulse excitation technique. Within experimental error, the aromaticity values in the range 0.75–0.90 correlate extremely well with the ratios (A2 = 0.93); the 11 samples investigated with ratios between 0.74 and 0.77 all have aromaticities in the range 0.75–0.81. Furthermore, the correlation holds for the coals investigated with high inertinite contents.