A novel test method is developed to measure the size and spatial distribution of surface defects in glass fibers. The test method utilizes a sample comprised of a lubricated single S2-glass fiber placed between two Kapton carrier films that is subjected to pure bending deformation over the length of the fiber. The degree of flexural strain is controlled by bending the sample over a loading surface of prescribed radius of curvature. The number density and spatial location of defects were measured using a confocal microscope. The same sample was then tested with a smaller radius of curvature surface to generate a higher flexural strain level to trigger additional fiber fractures at surface defects of smaller size. This sequence was repeated for loading surfaces with radii of curvatures ranging from 350 µm to 25 µm. Tests were conducted over 870 mm of fiber length to generate statistical data. For a 10-micron S2-glass fiber this corresponds to flexural failure strain in the range of 1.4 % (1.2 GPa) to 11.6 % (10.4 GPa) and defect size from 1572 nm to 21 nm, respectively. A map of defect size and spacing along the fiber length was generated from the experiments and the lognormal fitting curve of spacing was established for each defect size. This map of defect also was used to create the flexural strength distributions for different lengths ranging from 0.01 (10 µm) to 20 mm. These results are used to establish the limits of Weibull statistics commonly used to predict the strength at small length scales needed for multi-scale modeling. In addition, the experimental flexural strength at small lengths approaches the strength of S2-glass fiber predicted by molecular dynamic simulations at low strain rates (9.6 GPa). Overall, our test method provides unique data at small length scales that can be used for prediction of tensile failure of unidirectional composites where clustering of fiber breaks is dependent on size and location of defects in neighboring fibers.