The carbon-13 chemical shift tensors of meso-erythritol (1,2,3,4-butanetetrol, C4H10O4) were measured from two one-dimensional NMR spectra taken with the applied field perpendicular to the (110) and (101) crystal faces. Ab initio gauge invariant atomic orbital (GIAO) chemical shielding computations were used to assign the spectral lines to the carbons in the erythritol molecule and the molecules in the unit cell. The conformational disorder in erythritol was treated by taking the weighted average of the GIAO results for the two different conformations. The icosahedral shieldings computed with various weighting factors were then fitted to the experimental icosahedral shifts. Using the neutron diffraction structure the GIAO computations produced shieldings which correlate to the experimental chemical shift tensors with a 1.53 ppm standard deviation. The weighting factor which produced the best fit agrees with the occupancy percentage determined by neutron diffraction. GIAO computations were done for hypothetical O-H bond conformations in erythritol to investigate the effect of the hydroxyl dihedral angles on carbon-13 tensors.