Automated cell counting accuracy of the lens-free imaging technique is illustrated at various RBC densities, ranging from <50 000 cells/μL up to ~0.4 × 106 cells/μL. For each dilution level, at least 500 cells were automatically counted to estimate the cell density in each case. The reconstructed cell images yielded an absolute error rate of <5%, up to a cell density of ~0.4 × 106 cells/μL. The inset also illustrates a comparison of RBC volume histogram that is estimated based on holographic reconstructions against a commercially available hematology analyzer (Model Coulter LH750, Beckman Coulter), which showed a very good fit to our results.