  We examine the agreement between the observed and theoretical low-mass (< 0.8
solar masses) stellar main sequence mass-radius relationship by comparing
detached eclipsing binary (DEB) data with a new, large grid of stellar
evolution models. The new grid allows for a realistic variation in the age and
metallicity of the DEB population, characteristic of the local galactic
neighborhood. Overall, our models do a reasonable job of reproducing the
observational data. A large majority of the models match the observed stellar
radii to within 4%, with a mean absolute error of 2.3%. These results represent
a factor of two improvement compared to previous examinations of the low-mass
mass-radius relationship. The improved agreement between models and
observations brings the radius deviations within the limits imposed by
potential starspot-related uncertainties for 92% of the stars in our DEB
sample.
